/**
 * Prototype JavaScript framework, version 1.6.0.2
 *  (c) 2005-2008 Sam Stephenson
 *
 *  Prototype is freely distributable under the terms of an MIT-style license.
 *  For details, see the Prototype web site: http://www.prototypejs.org/
 *
 *--------------------------------------------------------------------------*/

var Prototype = {
  Version: '1.6.0.2',

  Browser: {
        IE: !! (window.attachEvent && !window.opera),
        Opera: !! window.opera,
    WebKit: navigator.userAgent.indexOf('AppleWebKit/') > -1,
    Gecko:  navigator.userAgent.indexOf('Gecko') > -1 && navigator.userAgent.indexOf('KHTML') == -1,
        MobileSafari: !! navigator.userAgent.match(/Apple.*Mobile.*Safari/)
  },

  BrowserFeatures: {
        XPath: !! document.evaluate,
        ElementExtensions: !! window.HTMLElement,
        SpecificElementExtensions: document.createElement('div').__proto__ && document.createElement('div').__proto__ !== document.createElement('form').__proto__
  },

  ScriptFragment: '<script[^>]*>([\\S\\s]*?)<\/script>',
  JSONFilter: /^\/\*-secure-([\s\S]*)\*\/\s*$/,

    emptyFunction: function() {},
    K: function(x) {
        return x;
    }
};

if (Prototype.Browser.MobileSafari) Prototype.BrowserFeatures.SpecificElementExtensions = false;


/* Based on Alex Arnell's inheritance implementation. */
var Class = {
  create: function() {
        var parent = null,
            properties = $A(arguments);
        if (Object.isFunction(properties[0])) parent = properties.shift();

    function klass() {
      this.initialize.apply(this, arguments);
    }

    Object.extend(klass, Class.Methods);
    klass.superclass = parent;
    klass.subclasses = [];

    if (parent) {
            var subclass = function() {};
      subclass.prototype = parent.prototype;
      klass.prototype = new subclass;
      parent.subclasses.push(klass);
    }

    for (var i = 0; i < properties.length; i++)
      klass.addMethods(properties[i]);

        if (!klass.prototype.initialize) klass.prototype.initialize = Prototype.emptyFunction;

    klass.prototype.constructor = klass;

    return klass;
  }
};

Class.Methods = {
  addMethods: function(source) {
    var ancestor   = this.superclass && this.superclass.prototype;
    var properties = Object.keys(source);

        if (!Object.keys({
            toString: true
        }).length) properties.push('toString', 'valueOf');

    for (var i = 0, length = properties.length; i < length; i++) {
            var property = properties[i],
                value = source[property];
            if (ancestor && Object.isFunction(value) && value.argumentNames().first() == '$super') {
                var method = value,
                    value = Object.extend((function(m) {
                        return function() {
                            return ancestor[m].apply(this, arguments);
                        };
        })(property).wrap(method), {
                        valueOf: function() {
                            return method;
                        },
                        toString: function() {
                            return method.toString();
                        }
        });
      }
      this.prototype[property] = value;
    }

    return this;
  }
};

var Abstract = {};

Object.extend = function(destination, source) {
  for (var property in source)
    destination[property] = source[property];
  return destination;
};

Object.extend(Object, {
  inspect: function(object) {
    try {
      if (Object.isUndefined(object)) return 'undefined';
      if (object === null) return 'null';
      return object.inspect ? object.inspect() : String(object);
    } catch (e) {
      if (e instanceof RangeError) return '...';
      throw e;
    }
  },

  toJSON: function(object) {
    var type = typeof object;
    switch (type) {
      case 'undefined':
      case 'function':
        case 'unknown':
            return;
        case 'boolean':
            return object.toString();
    }

    if (object === null) return 'null';
    if (object.toJSON) return object.toJSON();
    if (Object.isElement(object)) return;

    var results = [];
    for (var property in object) {
      var value = Object.toJSON(object[property]);
            if (!Object.isUndefined(value)) results.push(property.toJSON() + ': ' + value);
    }

    return '{' + results.join(', ') + '}';
  },

  toQueryString: function(object) {
    return $H(object).toQueryString();
  },

  toHTML: function(object) {
    return object && object.toHTML ? object.toHTML() : String.interpret(object);
  },

  keys: function(object) {
    var keys = [];
    for (var property in object)
      keys.push(property);
    return keys;
  },

  values: function(object) {
    var values = [];
    for (var property in object)
      values.push(object[property]);
    return values;
  },

  clone: function(object) {
        return Object.extend({}, object);
  },

  isElement: function(object) {
    return object && object.nodeType == 1;
  },

  isArray: function(object) {
        return object != null && typeof object == 'object' && 'splice' in object && 'join' in object;
  },

  isHash: function(object) {
    return object instanceof Hash;
  },

  isFunction: function(object) {
        return typeof object == 'function';
  },

  isString: function(object) {
        return typeof object == 'string';
  },

  isNumber: function(object) {
        return typeof object == 'number';
  },

  isUndefined: function(object) {
        return typeof object == 'undefined';
  }
});

Object.extend(Function.prototype, {
  argumentNames: function() {
        var names = this.toString().match(/^[\s\(]*function[^(]*\((.*?)\)/)[1].split(',').invoke('strip');
    return names.length == 1 && !names[0] ? [] : names;
  },

  bind: function() {
    if (arguments.length < 2 && Object.isUndefined(arguments[0])) return this;
        var __method = this,
            args = $A(arguments),
            object = args.shift();
    return function() {
      return __method.apply(object, args.concat($A(arguments)));
        };
  },

  bindAsEventListener: function() {
        var __method = this,
            args = $A(arguments),
            object = args.shift();
    return function(event) {
      return __method.apply(object, [event || window.event].concat(args));
        };
  },

  curry: function() {
    if (!arguments.length) return this;
        var __method = this,
            args = $A(arguments);
    return function() {
      return __method.apply(this, args.concat($A(arguments)));
        };
  },

  delay: function() {
        var __method = this,
            args = $A(arguments),
            timeout = args.shift() * 1000;
    return window.setTimeout(function() {
      return __method.apply(__method, args);
    }, timeout);
  },

  wrap: function(wrapper) {
    var __method = this;
    return function() {
      return wrapper.apply(this, [__method.bind(this)].concat($A(arguments)));
        };
  },

  methodize: function() {
    if (this._methodized) return this._methodized;
    var __method = this;
    return this._methodized = function() {
      return __method.apply(null, [this].concat($A(arguments)));
    };
  }
});

Function.prototype.defer = Function.prototype.delay.curry(0.01);

Date.prototype.toJSON = function() {
    return '"' + this.getUTCFullYear() + '-' + (this.getUTCMonth() + 1).toPaddedString(2) + '-' + this.getUTCDate().toPaddedString(2) + 'T' + this.getUTCHours().toPaddedString(2) + ':' + this.getUTCMinutes().toPaddedString(2) + ':' + this.getUTCSeconds().toPaddedString(2) + 'Z"';
};

var Try = {
  these: function() {
    var returnValue;

    for (var i = 0, length = arguments.length; i < length; i++) {
      var lambda = arguments[i];
      try {
        returnValue = lambda();
        break;
            } catch (e) {}
    }

    return returnValue;
  }
};

RegExp.prototype.match = RegExp.prototype.test;

RegExp.escape = function(str) {
  return String(str).replace(/([.*+?^=!:${}()|[\]\/\\])/g, '\\$1');
};

/*--------------------------------------------------------------------------*/

var PeriodicalExecuter = Class.create({
  initialize: function(callback, frequency) {
    this.callback = callback;
    this.frequency = frequency;
    this.currentlyExecuting = false;

    this.registerCallback();
  },

  registerCallback: function() {
    this.timer = setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
  },

  execute: function() {
    this.callback(this);
  },

  stop: function() {
    if (!this.timer) return;
    clearInterval(this.timer);
    this.timer = null;
  },

  onTimerEvent: function() {
    if (!this.currentlyExecuting) {
      try {
        this.currentlyExecuting = true;
        this.execute();
      } finally {
        this.currentlyExecuting = false;
      }
    }
  }
});
Object.extend(String, {
  interpret: function(value) {
    return value == null ? '' : String(value);
  },
  specialChar: {
    '\b': '\\b',
    '\t': '\\t',
    '\n': '\\n',
    '\f': '\\f',
    '\r': '\\r',
    '\\': '\\\\'
  }
});

Object.extend(String.prototype, {
  gsub: function(pattern, replacement) {
        var result = '',
            source = this,
            match;
    replacement = arguments.callee.prepareReplacement(replacement);

    while (source.length > 0) {
      if (match = source.match(pattern)) {
        result += source.slice(0, match.index);
        result += String.interpret(replacement(match));
        source  = source.slice(match.index + match[0].length);
      } else {
        result += source, source = '';
      }
    }
    return result;
  },

  sub: function(pattern, replacement, count) {
    replacement = this.gsub.prepareReplacement(replacement);
    count = Object.isUndefined(count) ? 1 : count;

    return this.gsub(pattern, function(match) {
      if (--count < 0) return match[0];
      return replacement(match);
    });
  },

  scan: function(pattern, iterator) {
    this.gsub(pattern, iterator);
    return String(this);
  },

  truncate: function(length, truncation) {
    length = length || 30;
    truncation = Object.isUndefined(truncation) ? '...' : truncation;
        return this.length > length ? this.slice(0, length - truncation.length) + truncation : String(this);
  },

  strip: function() {
    return this.replace(/^\s+/, '').replace(/\s+$/, '');
  },

  stripTags: function() {
    return this.replace(/<\/?[^>]+>/gi, '');
  },

  stripScripts: function() {
    return this.replace(new RegExp(Prototype.ScriptFragment, 'img'), '');
  },

  extractScripts: function() {
    var matchAll = new RegExp(Prototype.ScriptFragment, 'img');
    var matchOne = new RegExp(Prototype.ScriptFragment, 'im');
    return (this.match(matchAll) || []).map(function(scriptTag) {
      return (scriptTag.match(matchOne) || ['', ''])[1];
    });
  },

  evalScripts: function() {
        return this.extractScripts().map(function(script) {
            return eval(script);
        });
  },

  escapeHTML: function() {
    var self = arguments.callee;
    self.text.data = this;
    return self.div.innerHTML;
  },

  unescapeHTML: function() {
    var div = new Element('div');
    div.innerHTML = this.stripTags();
        return div.childNodes[0] ? (div.childNodes.length > 1 ? $A(div.childNodes).inject('', function(memo, node) {
            return memo + node.nodeValue;
        }) : div.childNodes[0].nodeValue) : '';
  },

  toQueryParams: function(separator) {
    var match = this.strip().match(/([^?#]*)(#.*)?$/);
        if (!match) return {};

        return match[1].split(separator || '&').inject({}, function(hash, pair) {
      if ((pair = pair.split('='))[0]) {
        var key = decodeURIComponent(pair.shift());
        var value = pair.length > 1 ? pair.join('=') : pair[0];
        if (value != undefined) value = decodeURIComponent(value);

        if (key in hash) {
          if (!Object.isArray(hash[key])) hash[key] = [hash[key]];
          hash[key].push(value);
        }
        else hash[key] = value;
      }
      return hash;
    });
  },

  toArray: function() {
    return this.split('');
  },

  succ: function() {
        return this.slice(0, this.length - 1) + String.fromCharCode(this.charCodeAt(this.length - 1) + 1);
  },

  times: function(count) {
    return count < 1 ? '' : new Array(count + 1).join(this);
  },

  camelize: function() {
        var parts = this.split('-'),
            len = parts.length;
    if (len == 1) return parts[0];

        var camelized = this.charAt(0) == '-' ? parts[0].charAt(0).toUpperCase() + parts[0].substring(1) : parts[0];

    for (var i = 1; i < len; i++)
      camelized += parts[i].charAt(0).toUpperCase() + parts[i].substring(1);

    return camelized;
  },

  capitalize: function() {
    return this.charAt(0).toUpperCase() + this.substring(1).toLowerCase();
  },

  underscore: function() {
        return this.gsub(/::/, '/').gsub(/([A-Z]+)([A-Z][a-z])/, '#{1}_#{2}').gsub(/([a-z\d])([A-Z])/, '#{1}_#{2}').gsub(/-/, '_').toLowerCase();
  },

  dasherize: function() {
        return this.gsub(/_/, '-');
  },

  inspect: function(useDoubleQuotes) {
    var escapedString = this.gsub(/[\x00-\x1f\\]/, function(match) {
      var character = String.specialChar[match[0]];
      return character ? character : '\\u00' + match[0].charCodeAt().toPaddedString(2, 16);
    });
    if (useDoubleQuotes) return '"' + escapedString.replace(/"/g, '\\"') + '"';
        return '"' + escapedString.replace(/'/g, '\\\'') + '"';
  },

  toJSON: function() {
    return this.inspect(true);
  },

  unfilterJSON: function(filter) {
    return this.sub(filter || Prototype.JSONFilter, '#{1}');
  },

  isJSON: function() {
    var str = this;
    if (str.blank()) return false;
    str = this.replace(/\\./g, '@').replace(/"[^"\\\n\r]*"/g, '');
    return (/^[,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t]*$/).test(str);
  },

  evalJSON: function(sanitize) {
    var json = this.unfilterJSON();
    try {
      if (!sanitize || json.isJSON()) return eval('(' + json + ')');
        } catch (e) {}
    throw new SyntaxError('Badly formed JSON string: ' + this.inspect());
  },

  include: function(pattern) {
    return this.indexOf(pattern) > -1;
  },

  startsWith: function(pattern) {
    return this.indexOf(pattern) === 0;
  },

  endsWith: function(pattern) {
    var d = this.length - pattern.length;
    return d >= 0 && this.lastIndexOf(pattern) === d;
  },

  empty: function() {
    return this == '';
  },

  blank: function() {
    return /^\s*$/.test(this);
  },

  interpolate: function(object, pattern) {
    return new Template(this, pattern).evaluate(object);
  }
});

if (Prototype.Browser.WebKit || Prototype.Browser.IE) Object.extend(String.prototype, {
  escapeHTML: function() {
        return this.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
  },
  unescapeHTML: function() {
        return this.replace(/&amp;/g, '&').replace(/&lt;/g, '<').replace(/&gt;/g, '>');
  }
});

String.prototype.gsub.prepareReplacement = function(replacement) {
  if (Object.isFunction(replacement)) return replacement;
  var template = new Template(replacement);
    return function(match) {
        return template.evaluate(match);
    };
};

String.prototype.parseQuery = String.prototype.toQueryParams;

Object.extend(String.prototype.escapeHTML, {
  div:  document.createElement('div'),
  text: document.createTextNode('')
});

with(String.prototype.escapeHTML) div.appendChild(text);

var Template = Class.create({
  initialize: function(template, pattern) {
    this.template = template.toString();
    this.pattern = pattern || Template.Pattern;
  },

  evaluate: function(object) {
        if (Object.isFunction(object.toTemplateReplacements)) object = object.toTemplateReplacements();

    return this.template.gsub(this.pattern, function(match) {
      if (object == null) return '';

      var before = match[1] || '';
      if (before == '\\') return match[2];

            var ctx = object,
                expr = match[3];
      var pattern = /^([^.[]+|\[((?:.*?[^\\])?)\])(\.|\[|$)/;
      match = pattern.exec(expr);
      if (match == null) return before;

      while (match != null) {
        var comp = match[1].startsWith('[') ? match[2].gsub('\\\\]', ']') : match[1];
        ctx = ctx[comp];
        if (null == ctx || '' == match[3]) break;
        expr = expr.substring('[' == match[3] ? match[1].length : match[0].length);
        match = pattern.exec(expr);
      }

      return before + String.interpret(ctx);
    });
  }
});
Template.Pattern = /(^|.|\r|\n)(#\{(.*?)\})/;

var $break = {};

var Enumerable = {
  each: function(iterator, context) {
    var index = 0;
    iterator = iterator.bind(context);
    try {
      this._each(function(value) {
        iterator(value, index++);
      });
    } catch (e) {
      if (e != $break) throw e;
    }
    return this;
  },

  eachSlice: function(number, iterator, context) {
    iterator = iterator ? iterator.bind(context) : Prototype.K;
        var index = -number,
            slices = [],
            array = this.toArray();
    while ((index += number) < array.length)
        slices.push(array.slice(index, index + number));
    return slices.collect(iterator, context);
  },

  all: function(iterator, context) {
    iterator = iterator ? iterator.bind(context) : Prototype.K;
    var result = true;
    this.each(function(value, index) {
            result = result && !! iterator(value, index);
      if (!result) throw $break;
    });
    return result;
  },

  any: function(iterator, context) {
    iterator = iterator ? iterator.bind(context) : Prototype.K;
    var result = false;
    this.each(function(value, index) {
            if (result = !! iterator(value, index)) throw $break;
    });
    return result;
  },

  collect: function(iterator, context) {
    iterator = iterator ? iterator.bind(context) : Prototype.K;
    var results = [];
    this.each(function(value, index) {
      results.push(iterator(value, index));
    });
    return results;
  },

  detect: function(iterator, context) {
    iterator = iterator.bind(context);
    var result;
    this.each(function(value, index) {
      if (iterator(value, index)) {
        result = value;
        throw $break;
      }
    });
    return result;
  },

  findAll: function(iterator, context) {
    iterator = iterator.bind(context);
    var results = [];
    this.each(function(value, index) {
            if (iterator(value, index)) results.push(value);
    });
    return results;
  },

  grep: function(filter, iterator, context) {
    iterator = iterator ? iterator.bind(context) : Prototype.K;
    var results = [];

        if (Object.isString(filter)) filter = new RegExp(filter);

    this.each(function(value, index) {
            if (filter.match(value)) results.push(iterator(value, index));
    });
    return results;
  },

  include: function(object) {
        if (Object.isFunction(this.indexOf)) if (this.indexOf(object) != -1) return true;

    var found = false;
    this.each(function(value) {
      if (value == object) {
        found = true;
        throw $break;
      }
    });
    return found;
  },

  inGroupsOf: function(number, fillWith) {
    fillWith = Object.isUndefined(fillWith) ? null : fillWith;
    return this.eachSlice(number, function(slice) {
            while (slice.length < number) slice.push(fillWith);
      return slice;
    });
  },

  inject: function(memo, iterator, context) {
    iterator = iterator.bind(context);
    this.each(function(value, index) {
      memo = iterator(memo, value, index);
    });
    return memo;
  },

  invoke: function(method) {
    var args = $A(arguments).slice(1);
    return this.map(function(value) {
      return value[method].apply(value, args);
    });
  },

  max: function(iterator, context) {
    iterator = iterator ? iterator.bind(context) : Prototype.K;
    var result;
    this.each(function(value, index) {
      value = iterator(value, index);
            if (result == null || value >= result) result = value;
    });
    return result;
  },

  min: function(iterator, context) {
    iterator = iterator ? iterator.bind(context) : Prototype.K;
    var result;
    this.each(function(value, index) {
      value = iterator(value, index);
            if (result == null || value < result) result = value;
    });
    return result;
  },

  partition: function(iterator, context) {
    iterator = iterator ? iterator.bind(context) : Prototype.K;
        var trues = [],
            falses = [];
    this.each(function(value, index) {
            (iterator(value, index) ? trues : falses).push(value);
    });
    return [trues, falses];
  },

  pluck: function(property) {
    var results = [];
    this.each(function(value) {
      results.push(value[property]);
    });
    return results;
  },

  reject: function(iterator, context) {
    iterator = iterator.bind(context);
    var results = [];
    this.each(function(value, index) {
            if (!iterator(value, index)) results.push(value);
    });
    return results;
  },

  sortBy: function(iterator, context) {
    iterator = iterator.bind(context);
    return this.map(function(value, index) {
            return {
                value: value,
                criteria: iterator(value, index)
            };
    }).sort(function(left, right) {
            var a = left.criteria,
                b = right.criteria;
      return a < b ? -1 : a > b ? 1 : 0;
    }).pluck('value');
  },

  toArray: function() {
    return this.map();
  },

  zip: function() {
        var iterator = Prototype.K,
            args = $A(arguments);
        if (Object.isFunction(args.last())) iterator = args.pop();

    var collections = [this].concat(args).map($A);
    return this.map(function(value, index) {
      return iterator(collections.pluck(index));
    });
  },

  size: function() {
    return this.toArray().length;
  },

  inspect: function() {
    return '#<Enumerable:' + this.toArray().inspect() + '>';
  }
};

Object.extend(Enumerable, {
  map:     Enumerable.collect,
  find:    Enumerable.detect,
  select:  Enumerable.findAll,
  filter:  Enumerable.findAll,
  member:  Enumerable.include,
  entries: Enumerable.toArray,
  every:   Enumerable.all,
  some:    Enumerable.any
});

function $A(iterable) {
  if (!iterable) return [];
  if (iterable.toArray) return iterable.toArray();
    var length = iterable.length || 0,
        results = new Array(length);
  while (length--) results[length] = iterable[length];
  return results;
}

if (Prototype.Browser.WebKit) {
  $A = function(iterable) {
    if (!iterable) return [];
        if (!(Object.isFunction(iterable) && iterable == '[object NodeList]') && iterable.toArray) return iterable.toArray();
        var length = iterable.length || 0,
            results = new Array(length);
    while (length--) results[length] = iterable[length];
    return results;
  };
}

Array.from = $A;

Object.extend(Array.prototype, Enumerable);

if (!Array.prototype._reverse) Array.prototype._reverse = Array.prototype.reverse;

Object.extend(Array.prototype, {
  _each: function(iterator) {
    for (var i = 0, length = this.length; i < length; i++)
      iterator(this[i]);
  },

  clear: function() {
    this.length = 0;
    return this;
  },

  first: function() {
    return this[0];
  },

  last: function() {
    return this[this.length - 1];
  },

  compact: function() {
    return this.select(function(value) {
      return value != null;
    });
  },

  flatten: function() {
    return this.inject([], function(array, value) {
            return array.concat(Object.isArray(value) ? value.flatten() : [value]);
    });
  },

  without: function() {
    var values = $A(arguments);
    return this.select(function(value) {
      return !values.include(value);
    });
  },

  reverse: function(inline) {
    return (inline !== false ? this : this.toArray())._reverse();
  },

  reduce: function() {
    return this.length > 1 ? this : this[0];
  },

  uniq: function(sorted) {
    return this.inject([], function(array, value, index) {
            if (0 == index || (sorted ? array.last() != value : !array.include(value))) array.push(value);
      return array;
    });
  },

  intersect: function(array) {
    return this.uniq().findAll(function(item) {
            return array.detect(function(value) {
                return item === value;
    });
        });
  },

  clone: function() {
    return [].concat(this);
  },

  size: function() {
    return this.length;
  },

  inspect: function() {
    return '[' + this.map(Object.inspect).join(', ') + ']';
  },

  toJSON: function() {
    var results = [];
    this.each(function(object) {
      var value = Object.toJSON(object);
      if (!Object.isUndefined(value)) results.push(value);
    });
    return '[' + results.join(', ') + ']';
  }
});

/* use native browser JS 1.6 implementation if available */
if (Object.isFunction(Array.prototype.forEach)) Array.prototype._each = Array.prototype.forEach;

if (!Array.prototype.indexOf) Array.prototype.indexOf = function(item, i) {
  i || (i = 0);
  var length = this.length;
  if (i < 0) i = length + i;
  for (; i < length; i++)
    if (this[i] === item) return i;
  return -1;
};

if (!Array.prototype.lastIndexOf) Array.prototype.lastIndexOf = function(item, i) {
  i = isNaN(i) ? this.length : (i < 0 ? this.length + i : i) + 1;
  var n = this.slice(0, i).reverse().indexOf(item);
  return (n < 0) ? n : i - n - 1;
};

Array.prototype.toArray = Array.prototype.clone;

function $w(string) {
  if (!Object.isString(string)) return [];
  string = string.strip();
  return string ? string.split(/\s+/) : [];
}

if (Prototype.Browser.Opera) {
  Array.prototype.concat = function() {
    var array = [];
    for (var i = 0, length = this.length; i < length; i++) array.push(this[i]);
    for (var i = 0, length = arguments.length; i < length; i++) {
      if (Object.isArray(arguments[i])) {
        for (var j = 0, arrayLength = arguments[i].length; j < arrayLength; j++)
          array.push(arguments[i][j]);
      } else {
        array.push(arguments[i]);
      }
    }
    return array;
  };
}
Object.extend(Number.prototype, {
  toColorPart: function() {
    return this.toPaddedString(2, 16);
  },

  succ: function() {
    return this + 1;
  },

  times: function(iterator) {
    $R(0, this, true).each(iterator);
    return this;
  },

  toPaddedString: function(length, radix) {
    var string = this.toString(radix || 10);
    return '0'.times(length - string.length) + string;
  },

  toJSON: function() {
    return isFinite(this) ? this.toString() : 'null';
  }
});

$w('abs round ceil floor').each(function(method) {
  Number.prototype[method] = Math[method].methodize();
});

function $H(object) {
  return new Hash(object);
};

var Hash = Class.create(Enumerable, (function() {

  function toQueryPair(key, value) {
    if (Object.isUndefined(value)) return key;
    return key + '=' + encodeURIComponent(String.interpret(value));
  }

  return {
    initialize: function(object) {
      this._object = Object.isHash(object) ? object.toObject() : Object.clone(object);
    },

    _each: function(iterator) {
      for (var key in this._object) {
                var value = this._object[key],
                    pair = [key, value];
        pair.key = key;
        pair.value = value;
        iterator(pair);
      }
    },

    set: function(key, value) {
      return this._object[key] = value;
    },

    get: function(key) {
      return this._object[key];
    },

    unset: function(key) {
      var value = this._object[key];
      delete this._object[key];
      return value;
    },

    toObject: function() {
      return Object.clone(this._object);
    },

    keys: function() {
      return this.pluck('key');
    },

    values: function() {
      return this.pluck('value');
    },

    index: function(value) {
      var match = this.detect(function(pair) {
        return pair.value === value;
      });
      return match && match.key;
    },

    merge: function(object) {
      return this.clone().update(object);
    },

    update: function(object) {
      return new Hash(object).inject(this, function(result, pair) {
        result.set(pair.key, pair.value);
        return result;
      });
    },

    toQueryString: function() {
      return this.map(function(pair) {
                var key = encodeURIComponent(pair.key),
                    values = pair.value;

        if (values && typeof values == 'object') {
                    if (Object.isArray(values)) return values.map(toQueryPair.curry(key)).join('&');
        }
        return toQueryPair(key, values);
      }).join('&');
    },

    inspect: function() {
      return '#<Hash:{' + this.map(function(pair) {
        return pair.map(Object.inspect).join(': ');
      }).join(', ') + '}>';
    },

    toJSON: function() {
      return Object.toJSON(this.toObject());
    },

    clone: function() {
      return new Hash(this);
    }
    };
})());

Hash.prototype.toTemplateReplacements = Hash.prototype.toObject;
Hash.from = $H;
var ObjectRange = Class.create(Enumerable, {
  initialize: function(start, end, exclusive) {
    this.start = start;
    this.end = end;
    this.exclusive = exclusive;
  },

  _each: function(iterator) {
    var value = this.start;
    while (this.include(value)) {
      iterator(value);
      value = value.succ();
    }
  },

  include: function(value) {
        if (value < this.start) return false;
        if (this.exclusive) return value < this.end;
    return value <= this.end;
  }
});

var $R = function(start, end, exclusive) {
  return new ObjectRange(start, end, exclusive);
};

var Ajax = {
  getTransport: function() {
    return Try.these(

        function() {
            return new XMLHttpRequest();
        }, function() {
            return new ActiveXObject('Msxml2.XMLHTTP');
        }, function() {
            return new ActiveXObject('Microsoft.XMLHTTP');
        }) || false;
  },

  activeRequestCount: 0
};

Ajax.Responders = {
  responders: [],

  _each: function(iterator) {
    this.responders._each(iterator);
  },

  register: function(responder) {
        if (!this.include(responder)) this.responders.push(responder);
  },

  unregister: function(responder) {
    this.responders = this.responders.without(responder);
  },

  dispatch: function(callback, request, transport, json) {
    this.each(function(responder) {
      if (Object.isFunction(responder[callback])) {
        try {
          responder[callback].apply(responder, [request, transport, json]);
                } catch (e) {}
      }
    });
  }
};

Object.extend(Ajax.Responders, Enumerable);

Ajax.Responders.register({
    onCreate: function() {
        Ajax.activeRequestCount++;
    },
    onComplete: function() {
        Ajax.activeRequestCount--;
    }
});

Ajax.Base = Class.create({
  initialize: function(options) {
    this.options = {
      method:       'post',
      asynchronous: true,
      contentType:  'application/x-www-form-urlencoded',
      encoding:     'UTF-8',
      parameters:   '',
      evalJSON:     true,
      evalJS:       true
    };
        Object.extend(this.options, options || {});

    this.options.method = this.options.method.toLowerCase();

        if (Object.isString(this.options.parameters)) this.options.parameters = this.options.parameters.toQueryParams();
        else if (Object.isHash(this.options.parameters)) this.options.parameters = this.options.parameters.toObject();
  }
});

Ajax.Request = Class.create(Ajax.Base, {
  _complete: false,

  initialize: function($super, url, options) {
    $super(options);
    this.transport = Ajax.getTransport();
    this.request(url);
  },

  request: function(url) {
    this.url = url;
    this.method = this.options.method;
    var params = Object.clone(this.options.parameters);

        if (!['get', 'post'].include(this.method)) { /* simulate other verbs over post */
      params['_method'] = this.method;
      this.method = 'post';
    }

    this.parameters = params;

        if (params = Object.toQueryString(params)) { /* when GET, append parameters to URL */
            if (this.method == 'get') this.url += (this.url.include('?') ? '&' : '?') + params;
            else if (/Konqueror|Safari|KHTML/.test(navigator.userAgent)) params += '&_=';
    }

    try {
      var response = new Ajax.Response(this);
      if (this.options.onCreate) this.options.onCreate(response);
      Ajax.Responders.dispatch('onCreate', this, response);

            this.transport.open(this.method.toUpperCase(), this.url, this.options.asynchronous);

      if (this.options.asynchronous) this.respondToReadyState.bind(this).defer(1);

      this.transport.onreadystatechange = this.onStateChange.bind(this);
      this.setRequestHeaders();

      this.body = this.method == 'post' ? (this.options.postBody || params) : null;
      this.transport.send(this.body);

      /* Force Firefox to handle ready state 4 for synchronous requests */
            if (!this.options.asynchronous && this.transport.overrideMimeType) this.onStateChange();

    }
    catch (e) {
      this.dispatchException(e);
    }
  },

  onStateChange: function() {
    var readyState = this.transport.readyState;
        if (readyState > 1 && !((readyState == 4) && this._complete)) this.respondToReadyState(this.transport.readyState);
  },

  setRequestHeaders: function() {
    var headers = {
      'X-Requested-With': 'XMLHttpRequest',
      'X-Prototype-Version': Prototype.Version,
      'Accept': 'text/javascript, text/html, application/xml, text/xml, */*'
    };

    if (this.method == 'post') {
            headers['Content-type'] = this.options.contentType + (this.options.encoding ? '; charset=' + this.options.encoding : '');

            /**
             * Force 'Connection: close' for older Mozilla browsers to work
       * around a bug where XMLHttpRequest sends an incorrect
       * Content-length header. See Mozilla Bugzilla #246651.
       */
            if (this.transport.overrideMimeType && (navigator.userAgent.match(/Gecko\/(\d{4})/) || [0, 2005])[1] < 2005) headers['Connection'] = 'close';
    }

        /* user-defined headers */
    if (typeof this.options.requestHeaders == 'object') {
      var extras = this.options.requestHeaders;

            if (Object.isFunction(extras.push)) for (var i = 0, length = extras.length; i < length; i += 2) headers[extras[i]] = extras[i + 1];
            else $H(extras).each(function(pair) {
                headers[pair.key] = pair.value;
            });
    }

    for (var name in headers)
      this.transport.setRequestHeader(name, headers[name]);
  },

  success: function() {
    var status = this.getStatus();
    return !status || (status >= 200 && status < 300);
  },

  getStatus: function() {
    try {
      return this.transport.status || 0;
        } catch (e) {
            return 0;
        }
  },

  respondToReadyState: function(readyState) {
        var state = Ajax.Request.Events[readyState],
            response = new Ajax.Response(this);

    if (state == 'Complete') {
      try {
        this._complete = true;
                (this.options['on' + response.status] || this.options['on' + (this.success() ? 'Success' : 'Failure')] || Prototype.emptyFunction)(response, response.headerJSON);
      } catch (e) {
        this.dispatchException(e);
      }

      var contentType = response.getHeader('Content-type');
            if (this.options.evalJS == 'force' || (this.options.evalJS && this.isSameOrigin() && contentType && contentType.match(/^\s*(text|application)\/(x-)?(java|ecma)script(;.*)?\s*$/i))) this.evalResponse();
    }

    try {
      (this.options['on' + state] || Prototype.emptyFunction)(response, response.headerJSON);
      Ajax.Responders.dispatch('on' + state, this, response, response.headerJSON);
    } catch (e) {
      this.dispatchException(e);
    }

        if (state == 'Complete') { /* avoid memory leak in MSIE: clean up */
      this.transport.onreadystatechange = Prototype.emptyFunction;
    }
  },

  isSameOrigin: function() {
    var m = this.url.match(/^\s*https?:\/\/[^\/]*/);
    return !m || (m[0] == '#{protocol}//#{domain}#{port}'.interpolate({
      protocol: location.protocol,
      domain: document.domain,
      port: location.port ? ':' + location.port : ''
    }));
  },

  getHeader: function(name) {
    try {
      return this.transport.getResponseHeader(name) || null;
        } catch (e) {
            return null;
        }
  },

  evalResponse: function() {
    try {
      return eval((this.transport.responseText || '').unfilterJSON());
    } catch (e) {
      this.dispatchException(e);
    }
  },

  dispatchException: function(exception) {
    (this.options.onException || Prototype.emptyFunction)(this, exception);
    Ajax.Responders.dispatch('onException', this, exception);
  }
});

Ajax.Request.Events = ['Uninitialized', 'Loading', 'Loaded', 'Interactive', 'Complete'];

Ajax.Response = Class.create({
    initialize: function(request) {
    this.request = request;
    var transport  = this.transport  = request.transport,
        readyState = this.readyState = transport.readyState;

        if ((readyState > 2 && !Prototype.Browser.IE) || readyState == 4) {
      this.status       = this.getStatus();
      this.statusText   = this.getStatusText();
      this.responseText = String.interpret(transport.responseText);
      this.headerJSON   = this._getHeaderJSON();
    }

        if (readyState == 4) {
      var xml = transport.responseXML;
      this.responseXML  = Object.isUndefined(xml) ? null : xml;
      this.responseJSON = this._getResponseJSON();
    }
  },

  status:      0,
  statusText: '',

  getStatus: Ajax.Request.prototype.getStatus,

  getStatusText: function() {
    try {
      return this.transport.statusText || '';
        } catch (e) {
            return '';
        }
  },

  getHeader: Ajax.Request.prototype.getHeader,

  getAllHeaders: function() {
    try {
      return this.getAllResponseHeaders();
        } catch (e) {
            return null;
        }
  },

  getResponseHeader: function(name) {
    return this.transport.getResponseHeader(name);
  },

  getAllResponseHeaders: function() {
    return this.transport.getAllResponseHeaders();
  },

  _getHeaderJSON: function() {
    var json = this.getHeader('X-JSON');
    if (!json) return null;
    json = decodeURIComponent(escape(json));
    try {
            return json.evalJSON(this.request.options.sanitizeJSON || !this.request.isSameOrigin());
    } catch (e) {
      this.request.dispatchException(e);
    }
  },

  _getResponseJSON: function() {
    var options = this.request.options;
        if (!options.evalJSON || (options.evalJSON != 'force' && !(this.getHeader('Content-type') || '').include('application/json')) || this.responseText.blank()) return null;
    try {
            return this.responseText.evalJSON(options.sanitizeJSON || !this.request.isSameOrigin());
    } catch (e) {
      this.request.dispatchException(e);
    }
  }
});

Ajax.Updater = Class.create(Ajax.Request, {
  initialize: function($super, container, url, options) {
    this.container = {
      success: (container.success || container),
      failure: (container.failure || (container.success ? null : container))
    };

    options = Object.clone(options);
    var onComplete = options.onComplete;
    options.onComplete = (function(response, json) {
      this.updateContent(response.responseText);
      if (Object.isFunction(onComplete)) onComplete(response, json);
    }).bind(this);

    $super(url, options);
  },

  updateContent: function(responseText) {
    var receiver = this.container[this.success() ? 'success' : 'failure'],
        options = this.options;

    if (!options.evalScripts) responseText = responseText.stripScripts();

    if (receiver = $(receiver)) {
      if (options.insertion) {
        if (Object.isString(options.insertion)) {
                    var insertion = {};
                    insertion[options.insertion] = responseText;
          receiver.insert(insertion);
        }
        else options.insertion(receiver, responseText);
      }
      else receiver.update(responseText);
    }
  }
});

Ajax.PeriodicalUpdater = Class.create(Ajax.Base, {
  initialize: function($super, container, url, options) {
    $super(options);
    this.onComplete = this.options.onComplete;

    this.frequency = (this.options.frequency || 2);
    this.decay = (this.options.decay || 1);

        this.updater = {};
    this.container = container;
    this.url = url;

    this.start();
  },

  start: function() {
    this.options.onComplete = this.updateComplete.bind(this);
    this.onTimerEvent();
  },

  stop: function() {
    this.updater.options.onComplete = undefined;
    clearTimeout(this.timer);
    (this.onComplete || Prototype.emptyFunction).apply(this, arguments);
  },

  updateComplete: function(response) {
    if (this.options.decay) {
            this.decay = (response.responseText == this.lastText ? this.decay * this.options.decay : 1);

      this.lastText = response.responseText;
    }
    this.timer = this.onTimerEvent.bind(this).delay(this.decay * this.frequency);
  },

  onTimerEvent: function() {
    this.updater = new Ajax.Updater(this.container, this.url, this.options);
  }
});

function $(element) {
  if (arguments.length > 1) {
    for (var i = 0, elements = [], length = arguments.length; i < length; i++)
      elements.push($(arguments[i]));
    return elements;
  }
    if (Object.isString(element)) element = document.getElementById(element);
  return Element.extend(element);
}

if (Prototype.BrowserFeatures.XPath) {
  document._getElementsByXPath = function(expression, parentElement) {
    var results = [];
        var query = document.evaluate(expression, $(parentElement) || document, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
    for (var i = 0, length = query.snapshotLength; i < length; i++)
      results.push(Element.extend(query.snapshotItem(i)));
    return results;
  };
}

/*--------------------------------------------------------------------------*/

if (!window.Node) var Node = {};

if (!Node.ELEMENT_NODE) { /* DOM level 2 ECMAScript Language Binding */
  Object.extend(Node, {
    ELEMENT_NODE: 1,
    ATTRIBUTE_NODE: 2,
    TEXT_NODE: 3,
    CDATA_SECTION_NODE: 4,
    ENTITY_REFERENCE_NODE: 5,
    ENTITY_NODE: 6,
    PROCESSING_INSTRUCTION_NODE: 7,
    COMMENT_NODE: 8,
    DOCUMENT_NODE: 9,
    DOCUMENT_TYPE_NODE: 10,
    DOCUMENT_FRAGMENT_NODE: 11,
    NOTATION_NODE: 12
  });
}

(function() {
  var element = this.Element;
  this.Element = function(tagName, attributes) {
        attributes = attributes || {};
    tagName = tagName.toLowerCase();
    var cache = Element.cache;
    if (Prototype.Browser.IE && attributes.name) {
      tagName = '<' + tagName + ' name="' + attributes.name + '">';
      delete attributes.name;
      return Element.writeAttribute(document.createElement(tagName), attributes);
    }
    if (!cache[tagName]) cache[tagName] = Element.extend(document.createElement(tagName));
    return Element.writeAttribute(cache[tagName].cloneNode(false), attributes);
  };
    Object.extend(this.Element, element || {});
}).call(window);

Element.cache = {};

Element.Methods = {
  visible: function(element) {
    return $(element).style.display != 'none';
  },

  toggle: function(element) {
    element = $(element);
    Element[Element.visible(element) ? 'hide' : 'show'](element);
    return element;
  },

  hide: function(element) {
    $(element).style.display = 'none';
    return element;
  },

  show: function(element) {
    $(element).style.display = '';
    return element;
  },

  remove: function(element) {
    element = $(element);
    element.parentNode.removeChild(element);
    return element;
  },

  update: function(element, content) {
    element = $(element);
    if (content && content.toElement) content = content.toElement();
    if (Object.isElement(content)) return element.update().insert(content);
    content = Object.toHTML(content);
    element.innerHTML = content.stripScripts();
    content.evalScripts.bind(content).defer();
    return element;
  },

  replace: function(element, content) {
    element = $(element);
    if (content && content.toElement) content = content.toElement();
    else if (!Object.isElement(content)) {
      content = Object.toHTML(content);
      var range = element.ownerDocument.createRange();
      range.selectNode(element);
      content.evalScripts.bind(content).defer();
      content = range.createContextualFragment(content.stripScripts());
    }
    element.parentNode.replaceChild(content, element);
    return element;
  },

  insert: function(element, insertions) {
    element = $(element);

        if (Object.isString(insertions) || Object.isNumber(insertions) || Object.isElement(insertions) || (insertions && (insertions.toElement || insertions.toHTML))) insertions = {
            bottom: insertions
        };

    var content, insert, tagName, childNodes;

    for (var position in insertions) {
      content  = insertions[position];
      position = position.toLowerCase();
      insert = Element._insertionTranslations[position];

      if (content && content.toElement) content = content.toElement();
      if (Object.isElement(content)) {
        insert(element, content);
        continue;
      }

      content = Object.toHTML(content);

            tagName = ((position == 'before' || position == 'after') ? element.parentNode : element).tagName.toUpperCase();

      childNodes = Element._getContentFromAnonymousElement(tagName, content.stripScripts());

      if (position == 'top' || position == 'after') childNodes.reverse();
      childNodes.each(insert.curry(element));

      content.evalScripts.bind(content).defer();
    }

    return element;
  },

  wrap: function(element, wrapper, attributes) {
    element = $(element);
        if (Object.isElement(wrapper)) $(wrapper).writeAttribute(attributes || {});
    else if (Object.isString(wrapper)) wrapper = new Element(wrapper, attributes);
    else wrapper = new Element('div', wrapper);
        if (element.parentNode) element.parentNode.replaceChild(wrapper, element);
    wrapper.appendChild(element);
    return wrapper;
  },

  inspect: function(element) {
    element = $(element);
    var result = '<' + element.tagName.toLowerCase();
        $H({
            'id': 'id',
            'className': 'class'
        }).each(function(pair) {
            var property = pair.first(),
                attribute = pair.last();
      var value = (element[property] || '').toString();
      if (value) result += ' ' + attribute + '=' + value.inspect(true);
    });
    return result + '>';
  },

  recursivelyCollect: function(element, property) {
    element = $(element);
    var elements = [];
    while (element = element[property])
        if (element.nodeType == 1) elements.push(Element.extend(element));
    return elements;
  },

  ancestors: function(element) {
    return $(element).recursivelyCollect('parentNode');
  },

  descendants: function(element) {
        return $(element).select('*');
  },

  firstDescendant: function(element) {
    element = $(element).firstChild;
    while (element && element.nodeType != 1) element = element.nextSibling;
    return $(element);
  },

  immediateDescendants: function(element) {
    if (!(element = $(element).firstChild)) return [];
    while (element && element.nodeType != 1) element = element.nextSibling;
    if (element) return [element].concat($(element).nextSiblings());
    return [];
  },

  previousSiblings: function(element) {
    return $(element).recursivelyCollect('previousSibling');
  },

  nextSiblings: function(element) {
    return $(element).recursivelyCollect('nextSibling');
  },

  siblings: function(element) {
    element = $(element);
    return element.previousSiblings().reverse().concat(element.nextSiblings());
  },

  match: function(element, selector) {
        if (Object.isString(selector)) selector = new Selector(selector);
    return selector.match($(element));
  },

  up: function(element, expression, index) {
    element = $(element);
    if (arguments.length == 1) return $(element.parentNode);
    var ancestors = element.ancestors();
        return Object.isNumber(expression) ? ancestors[expression] : Selector.findElement(ancestors, expression, index);
  },

  down: function(element, expression, index) {
    element = $(element);
    if (arguments.length == 1) return element.firstDescendant();
        return Object.isNumber(expression) ? element.descendants()[expression] : element.select(expression)[index || 0];
  },

  previous: function(element, expression, index) {
    element = $(element);
    if (arguments.length == 1) return $(Selector.handlers.previousElementSibling(element));
    var previousSiblings = element.previousSiblings();
        return Object.isNumber(expression) ? previousSiblings[expression] : Selector.findElement(previousSiblings, expression, index);
  },

  next: function(element, expression, index) {
    element = $(element);
    if (arguments.length == 1) return $(Selector.handlers.nextElementSibling(element));
    var nextSiblings = element.nextSiblings();
        return Object.isNumber(expression) ? nextSiblings[expression] : Selector.findElement(nextSiblings, expression, index);
  },

  select: function() {
        var args = $A(arguments),
            element = $(args.shift());
    return Selector.findChildElements(element, args);
  },

  adjacent: function() {
        var args = $A(arguments),
            element = $(args.shift());
    return Selector.findChildElements(element.parentNode, args).without(element);
  },

  identify: function(element) {
    element = $(element);
        var id = element.readAttribute('id'),
            self = arguments.callee;
    if (id) return id;
        do {
            id = 'anonymous_element_' + self.counter++;
        } while ($(id));
    element.writeAttribute('id', id);
    return id;
  },

  readAttribute: function(element, name) {
    element = $(element);
    if (Prototype.Browser.IE) {
      var t = Element._attributeTranslations.read;
      if (t.values[name]) return t.values[name](element, name);
      if (t.names[name]) name = t.names[name];
      if (name.include(':')) {
                return (!element.attributes || !element.attributes[name]) ? null : element.attributes[name].value;
      }
    }
    return element.getAttribute(name);
  },

  writeAttribute: function(element, name, value) {
    element = $(element);
        var attributes = {},
            t = Element._attributeTranslations.write;

    if (typeof name == 'object') attributes = name;
    else attributes[name] = Object.isUndefined(value) ? true : value;

    for (var attr in attributes) {
      name = t.names[attr] || attr;
      value = attributes[attr];
      if (t.values[attr]) name = t.values[attr](element, value);
            if (value === false || value === null) element.removeAttribute(name);
            else if (value === true) element.setAttribute(name, name);
      else element.setAttribute(name, value);
    }
    return element;
  },

  getHeight: function(element) {
    return $(element).getDimensions().height;
  },

  getWidth: function(element) {
    return $(element).getDimensions().width;
  },

  classNames: function(element) {
    return new Element.ClassNames(element);
  },

  hasClassName: function(element, className) {
    if (!(element = $(element))) return;
    var elementClassName = element.className;
        return (elementClassName.length > 0 && (elementClassName == className || new RegExp('(^|\\s)' + className + '(\\s|$)').test(elementClassName)));
  },

  addClassName: function(element, className) {
    if (!(element = $(element))) return;
        if (!element.hasClassName(className)) element.className += (element.className ? ' ' : '') + className;
    return element;
  },

  removeClassName: function(element, className) {
    if (!(element = $(element))) return;
    element.className = element.className.replace(
        new RegExp('(^|\\s+)' + className + '(\\s+|$)'), ' ').strip();
    return element;
  },

  toggleClassName: function(element, className) {
    if (!(element = $(element))) return;
        return element[element.hasClassName(className) ? 'removeClassName' : 'addClassName'](className);
  },

    /* removes whitespace-only text node children */
  cleanWhitespace: function(element) {
    element = $(element);
    var node = element.firstChild;
    while (node) {
      var nextNode = node.nextSibling;
            if (node.nodeType == 3 && !/\S/.test(node.nodeValue)) element.removeChild(node);
      node = nextNode;
    }
    return element;
  },

  empty: function(element) {
    return $(element).innerHTML.blank();
  },

  descendantOf: function(element, ancestor) {
    element = $(element), ancestor = $(ancestor);
    var originalAncestor = ancestor;

        if (element.compareDocumentPosition) return (element.compareDocumentPosition(ancestor) & 8) === 8;

    if (element.sourceIndex && !Prototype.Browser.Opera) {
            var e = element.sourceIndex,
                a = ancestor.sourceIndex,
       nextAncestor = ancestor.nextSibling;
      if (!nextAncestor) {
                do {
                    ancestor = ancestor.parentNode;
                }
        while (!(nextAncestor = ancestor.nextSibling) && ancestor.parentNode);
      }
            if (nextAncestor && nextAncestor.sourceIndex) return (e > a && e < nextAncestor.sourceIndex);
    }

    while (element = element.parentNode)
      if (element == originalAncestor) return true;
    return false;
  },

  scrollTo: function(element) {
    element = $(element);
    var pos = element.cumulativeOffset();
    window.scrollTo(pos[0], pos[1]);
    return element;
  },

  getStyle: function(element, style) {
    element = $(element);
    style = style == 'float' ? 'cssFloat' : style.camelize();
    var value = element.style[style];
    if (!value) {
      var css = document.defaultView.getComputedStyle(element, null);
      value = css ? css[style] : null;
    }
    if (style == 'opacity') return value ? parseFloat(value) : 1.0;
    return value == 'auto' ? null : value;
  },

  getOpacity: function(element) {
    return $(element).getStyle('opacity');
  },

  setStyle: function(element, styles) {
    element = $(element);
        var elementStyle = element.style,
            match;
    if (Object.isString(styles)) {
      element.style.cssText += ';' + styles;
            return styles.include('opacity') ? element.setOpacity(styles.match(/opacity:\s*(\d?\.?\d*)/)[1]) : element;
    }
    for (var property in styles)
      if (property == 'opacity') element.setOpacity(styles[property]);
        else elementStyle[(property == 'float' || property == 'cssFloat') ? (Object.isUndefined(elementStyle.styleFloat) ? 'cssFloat' : 'styleFloat') : property] = styles[property];

    return element;
  },

  setOpacity: function(element, value) {
    element = $(element);
        element.style.opacity = (value == 1 || value === '') ? '' : (value < 0.00001) ? 0 : value;
    return element;
  },

  getDimensions: function(element) {
    element = $(element);
    var display = $(element).getStyle('display');
        if (display != 'none' && display != null) /* Safari bug */
        return {
            width: element.offsetWidth,
            height: element.offsetHeight
        };

        /* All *Width and *Height properties give 0 on elements with display none, */
        /* so enable the element temporarily */
    var els = element.style;
    var originalVisibility = els.visibility;
    var originalPosition = els.position;
    var originalDisplay = els.display;
    els.visibility = 'hidden';
    els.position = 'absolute';
    els.display = 'block';
    var originalWidth = element.clientWidth;
    var originalHeight = element.clientHeight;
    els.display = originalDisplay;
    els.position = originalPosition;
    els.visibility = originalVisibility;
        return {
            width: originalWidth,
            height: originalHeight
        };
  },

  makePositioned: function(element) {
    element = $(element);
    var pos = Element.getStyle(element, 'position');
    if (pos == 'static' || !pos) {
      element._madePositioned = true;
            element.style.position = 'relative'; /* Opera returns the offset relative to the positioning context, when an */
            /* element is position relative but top and left have not been defined */
      if (window.opera) {
        element.style.top = 0;
        element.style.left = 0;
      }
    }
    return element;
  },

  undoPositioned: function(element) {
    element = $(element);
    if (element._madePositioned) {
      element._madePositioned = undefined;
      element.style.position =
        element.style.top =
        element.style.left =
        element.style.bottom =
        element.style.right = '';
    }
    return element;
  },

  makeClipping: function(element) {
    element = $(element);
    if (element._overflow) return element;
    element._overflow = Element.getStyle(element, 'overflow') || 'auto';
        if (element._overflow !== 'hidden') element.style.overflow = 'hidden';
    return element;
  },

  undoClipping: function(element) {
    element = $(element);
    if (!element._overflow) return element;
    element.style.overflow = element._overflow == 'auto' ? '' : element._overflow;
    element._overflow = null;
    return element;
  },

  cumulativeOffset: function(element) {
        var valueT = 0,
            valueL = 0;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;
      element = element.offsetParent;
    } while (element);
    return Element._returnOffset(valueL, valueT);
  },

  positionedOffset: function(element) {
        var valueT = 0,
            valueL = 0;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;
      element = element.offsetParent;
      if (element) {
        if (element.tagName == 'BODY') break;
        var p = Element.getStyle(element, 'position');
        if (p !== 'static') break;
      }
    } while (element);
    return Element._returnOffset(valueL, valueT);
  },

  absolutize: function(element) {
    element = $(element);
        if (element.getStyle('position') == 'absolute') return; /* Position.prepare(); // To be done manually by Scripty when it needs it. */

    var offsets = element.positionedOffset();
    var top     = offsets[1];
    var left    = offsets[0];
    var width   = element.clientWidth;
    var height  = element.clientHeight;

    element._originalLeft   = left - parseFloat(element.style.left  || 0);
    element._originalTop    = top  - parseFloat(element.style.top || 0);
    element._originalWidth  = element.style.width;
    element._originalHeight = element.style.height;

    element.style.position = 'absolute';
    element.style.top    = top + 'px';
    element.style.left   = left + 'px';
    element.style.width  = width + 'px';
    element.style.height = height + 'px';
    return element;
  },

  relativize: function(element) {
    element = $(element);
        if (element.getStyle('position') == 'relative') return; /* Position.prepare(); // To be done manually by Scripty when it needs it. */

    element.style.position = 'relative';
    var top  = parseFloat(element.style.top  || 0) - (element._originalTop || 0);
    var left = parseFloat(element.style.left || 0) - (element._originalLeft || 0);

    element.style.top    = top + 'px';
    element.style.left   = left + 'px';
    element.style.height = element._originalHeight;
    element.style.width  = element._originalWidth;
    return element;
  },

  cumulativeScrollOffset: function(element) {
        var valueT = 0,
            valueL = 0;
    do {
      valueT += element.scrollTop  || 0;
      valueL += element.scrollLeft || 0;
      element = element.parentNode;
    } while (element);
    return Element._returnOffset(valueL, valueT);
  },

  getOffsetParent: function(element) {
    if (element.offsetParent) return $(element.offsetParent);
    if (element == document.body) return $(element);

    while ((element = element.parentNode) && element != document.body)
        if (Element.getStyle(element, 'position') != 'static') return $(element);

    return $(document.body);
  },

  viewportOffset: function(forElement) {
        var valueT = 0,
            valueL = 0;

    var element = forElement;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;

            /* Safari fix */
            if (element.offsetParent == document.body && Element.getStyle(element, 'position') == 'absolute') break;

    } while (element = element.offsetParent);

    element = forElement;
    do {
      if (!Prototype.Browser.Opera || element.tagName == 'BODY') {
        valueT -= element.scrollTop  || 0;
        valueL -= element.scrollLeft || 0;
      }
    } while (element = element.parentNode);

    return Element._returnOffset(valueL, valueT);
  },

  clonePosition: function(element, source) {
    var options = Object.extend({
      setLeft:    true,
      setTop:     true,
      setWidth:   true,
      setHeight:  true,
      offsetTop:  0,
      offsetLeft: 0
        }, arguments[2] || {});

        /* find page position of source */
    source = $(source);
    var p = source.viewportOffset();

        /* find coordinate system to use */
    element = $(element);
    var delta = [0, 0];
    var parent = null;
/* delta [0,0] will do fine with position: fixed elements,
    position:absolute needs offsetParent deltas */
    if (Element.getStyle(element, 'position') == 'absolute') {
      parent = element.getOffsetParent();
      delta = parent.viewportOffset();
    }

        /* correct by body offsets (fixes Safari) */
    if (parent == document.body) {
      delta[0] -= document.body.offsetLeft;
      delta[1] -= document.body.offsetTop;
    }

        /* set position */
    if (options.setLeft)   element.style.left  = (p[0] - delta[0] + options.offsetLeft) + 'px';
    if (options.setTop)    element.style.top   = (p[1] - delta[1] + options.offsetTop) + 'px';
    if (options.setWidth)  element.style.width = source.offsetWidth + 'px';
    if (options.setHeight) element.style.height = source.offsetHeight + 'px';
    return element;
  }
};

Element.Methods.identify.counter = 1;

Object.extend(Element.Methods, {
  getElementsBySelector: Element.Methods.select,
  childElements: Element.Methods.immediateDescendants
});

Element._attributeTranslations = {
  write: {
    names: {
      className: 'class',
      htmlFor:   'for'
    },
        values: {}
  }
};

if (Prototype.Browser.Opera) {
  Element.Methods.getStyle = Element.Methods.getStyle.wrap(

    function(proceed, element, style) {
      switch (style) {
        case 'left':
        case 'top':
        case 'right':
        case 'bottom':
          if (proceed(element, 'position') === 'static') return null;
        case 'height':
        case 'width':
            /* returns '0px' for hidden elements; we want it to return null */
          if (!Element.visible(element)) return null;

/* returns the border-box dimensions rather than the content-box
          dimensions, so we subtract padding and borders from the value */
          var dim = parseInt(proceed(element, style), 10);

            if (dim !== element['offset' + style.capitalize()]) return dim + 'px';

          var properties;
          if (style === 'height') {
            properties = ['border-top-width', 'padding-top',
             'padding-bottom', 'border-bottom-width'];
          }
          else {
            properties = ['border-left-width', 'padding-left',
             'padding-right', 'border-right-width'];
          }
          return properties.inject(dim, function(memo, property) {
            var val = proceed(element, property);
            return val === null ? memo : memo - parseInt(val, 10);
          }) + 'px';
        default:
            return proceed(element, style);
      }
    });

  Element.Methods.readAttribute = Element.Methods.readAttribute.wrap(

    function(proceed, element, attribute) {
      if (attribute === 'title') return element.title;
      return proceed(element, attribute);
    });
}

else if (Prototype.Browser.IE) {
/* IE doesn't report offsets correctly for static elements, so we change them
  to 'relative' to get the values, then change them back. */
  Element.Methods.getOffsetParent = Element.Methods.getOffsetParent.wrap(

    function(proceed, element) {
      element = $(element);
      var position = element.getStyle('position');
      if (position !== 'static') return proceed(element);
        element.setStyle({
            position: 'relative'
        });
      var value = proceed(element);
        element.setStyle({
            position: position
        });
      return value;
    });

  $w('positionedOffset viewportOffset').each(function(method) {
    Element.Methods[method] = Element.Methods[method].wrap(

      function(proceed, element) {
        element = $(element);
        var position = element.getStyle('position');
        if (position !== 'static') return proceed(element);
/* Trigger hasLayout on the offset parent so that IE6 reports
        accurate offsetTop and offsetLeft values for position: fixed. */
        var offsetParent = element.getOffsetParent();
            if (offsetParent && offsetParent.getStyle('position') === 'fixed') offsetParent.setStyle({
                zoom: 1
            });
            element.setStyle({
                position: 'relative'
            });
        var value = proceed(element);
            element.setStyle({
                position: position
            });
        return value;
  });
    });

  Element.Methods.getStyle = function(element, style) {
    element = $(element);
    style = (style == 'float' || style == 'cssFloat') ? 'styleFloat' : style.camelize();
    var value = element.style[style];
    if (!value && element.currentStyle) value = element.currentStyle[style];

    if (style == 'opacity') {
            if (value = (element.getStyle('filter') || '').match(/alpha\(opacity=(.*)\)/)) if (value[1]) return parseFloat(value[1]) / 100;
      return 1.0;
    }

    if (value == 'auto') {
            if ((style == 'width' || style == 'height') && (element.getStyle('display') != 'none')) return element['offset' + style.capitalize()] + 'px';
      return null;
    }
    return value;
  };

  Element.Methods.setOpacity = function(element, value) {
        function stripAlpha(filter) {
            return filter.replace(/alpha\([^\)]*\)/gi, '');
    }
    element = $(element);
    var currentStyle = element.currentStyle;
        if ((currentStyle && !currentStyle.hasLayout) || (!currentStyle && element.style.zoom == 'normal')) element.style.zoom = 1;

        var filter = element.getStyle('filter'),
            style = element.style;
    if (value == 1 || value === '') {
            (filter = stripAlpha(filter)) ? style.filter = filter : style.removeAttribute('filter');
      return element;
    } else if (value < 0.00001) value = 0;
        style.filter = stripAlpha(filter) + 'alpha(opacity=' + (value * 100) + ')';
    return element;
  };

  Element._attributeTranslations = {
    read: {
      names: {
        'class': 'className',
        'for':   'htmlFor'
      },
      values: {
        _getAttr: function(element, attribute) {
          return element.getAttribute(attribute, 2);
        },
        _getAttrNode: function(element, attribute) {
          var node = element.getAttributeNode(attribute);
                    return node ? node.value : '';
        },
        _getEv: function(element, attribute) {
          attribute = element.getAttribute(attribute);
          return attribute ? attribute.toString().slice(23, -2) : null;
        },
        _flag: function(element, attribute) {
          return $(element).hasAttribute(attribute) ? attribute : null;
        },
        style: function(element) {
          return element.style.cssText.toLowerCase();
        },
        title: function(element) {
          return element.title;
        }
      }
    }
  };

  Element._attributeTranslations.write = {
    names: Object.extend({
      cellpadding: 'cellPadding',
      cellspacing: 'cellSpacing'
    }, Element._attributeTranslations.read.names),
    values: {
      checked: function(element, value) {
                element.checked = !! value;
      },

      style: function(element, value) {
        element.style.cssText = value ? value : '';
      }
    }
  };

  Element._attributeTranslations.has = {};

    $w('colSpan rowSpan vAlign dateTime accessKey tabIndex ' + 'encType maxLength readOnly longDesc').each(function(attr) {
    Element._attributeTranslations.write.names[attr.toLowerCase()] = attr;
    Element._attributeTranslations.has[attr.toLowerCase()] = attr;
  });

  (function(v) {
    Object.extend(v, {
      href:        v._getAttr,
      src:         v._getAttr,
      type:        v._getAttr,
      action:      v._getAttrNode,
      disabled:    v._flag,
      checked:     v._flag,
      readonly:    v._flag,
      multiple:    v._flag,
      onload:      v._getEv,
      onunload:    v._getEv,
      onclick:     v._getEv,
      ondblclick:  v._getEv,
      onmousedown: v._getEv,
      onmouseup:   v._getEv,
      onmouseover: v._getEv,
      onmousemove: v._getEv,
      onmouseout:  v._getEv,
      onfocus:     v._getEv,
      onblur:      v._getEv,
      onkeypress:  v._getEv,
      onkeydown:   v._getEv,
      onkeyup:     v._getEv,
      onsubmit:    v._getEv,
      onreset:     v._getEv,
      onselect:    v._getEv,
      onchange:    v._getEv
    });
  })(Element._attributeTranslations.read.values);
}

else if (Prototype.Browser.Gecko && /rv:1\.8\.0/.test(navigator.userAgent)) {
  Element.Methods.setOpacity = function(element, value) {
    element = $(element);
        element.style.opacity = (value == 1) ? 0.999999 : (value === '') ? '' : (value < 0.00001) ? 0 : value;
    return element;
  };
}

else if (Prototype.Browser.WebKit) {
  Element.Methods.setOpacity = function(element, value) {
    element = $(element);
        element.style.opacity = (value == 1 || value === '') ? '' : (value < 0.00001) ? 0 : value;

        if (value == 1) if (element.tagName == 'IMG' && element.width) {
            element.width++;
            element.width--;
      } else try {
        var n = document.createTextNode(' ');
        element.appendChild(n);
        element.removeChild(n);
        } catch (e) {}

    return element;
  };

    /** 
     * Safari returns margins on body which is incorrect if the child is absolutely
     * positioned.  For performance reasons, redefine Element#cumulativeOffset for
     * KHTML/WebKit only. 
     */
  Element.Methods.cumulativeOffset = function(element) {
        var valueT = 0,
            valueL = 0;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;
            if (element.offsetParent == document.body) if (Element.getStyle(element, 'position') == 'absolute') break;

      element = element.offsetParent;
    } while (element);

    return Element._returnOffset(valueL, valueT);
  };
}

if (Prototype.Browser.IE || Prototype.Browser.Opera) { /* IE and Opera are missing .innerHTML support for TABLE-related and SELECT elements */
  Element.Methods.update = function(element, content) {
    element = $(element);

    if (content && content.toElement) content = content.toElement();
    if (Object.isElement(content)) return element.update().insert(content);

    content = Object.toHTML(content);
    var tagName = element.tagName.toUpperCase();

    if (tagName in Element._insertionTranslations.tags) {
            $A(element.childNodes).each(function(node) {
                element.removeChild(node);
            });
            Element._getContentFromAnonymousElement(tagName, content.stripScripts()).each(function(node) {
                element.appendChild(node);
            });
    }
    else element.innerHTML = content.stripScripts();

    content.evalScripts.bind(content).defer();
    return element;
  };
}

if ('outerHTML' in document.createElement('div')) {
  Element.Methods.replace = function(element, content) {
    element = $(element);

    if (content && content.toElement) content = content.toElement();
    if (Object.isElement(content)) {
      element.parentNode.replaceChild(content, element);
      return element;
    }

    content = Object.toHTML(content);
        var parent = element.parentNode,
            tagName = parent.tagName.toUpperCase();

    if (Element._insertionTranslations.tags[tagName]) {
      var nextSibling = element.next();
      var fragments = Element._getContentFromAnonymousElement(tagName, content.stripScripts());
      parent.removeChild(element);
            if (nextSibling) fragments.each(function(node) {
                parent.insertBefore(node, nextSibling);
            });
            else fragments.each(function(node) {
                parent.appendChild(node);
            });
    }
    else element.outerHTML = content.stripScripts();

    content.evalScripts.bind(content).defer();
    return element;
  };
}

Element._returnOffset = function(l, t) {
  var result = [l, t];
  result.left = l;
  result.top = t;
  return result;
};

Element._getContentFromAnonymousElement = function(tagName, html) {
    var div = new Element('div'),
        t = Element._insertionTranslations.tags[tagName];
  if (t) {
    div.innerHTML = t[0] + html + t[1];
        t[2].times(function() {
            div = div.firstChild;
        });
  } else div.innerHTML = html;
  return $A(div.childNodes);
};

Element._insertionTranslations = {
  before: function(element, node) {
    element.parentNode.insertBefore(node, element);
  },
  top: function(element, node) {
    element.insertBefore(node, element.firstChild);
  },
  bottom: function(element, node) {
    element.appendChild(node);
  },
  after: function(element, node) {
    element.parentNode.insertBefore(node, element.nextSibling);
  },
  tags: {
    TABLE:  ['<table>',                '</table>',                   1],
    TBODY:  ['<table><tbody>',         '</tbody></table>',           2],
    TR:     ['<table><tbody><tr>',     '</tr></tbody></table>',      3],
    TD:     ['<table><tbody><tr><td>', '</td></tr></tbody></table>', 4],
    SELECT: ['<select>',               '</select>',                  1]
  }
};

(function() {
  Object.extend(this.tags, {
    THEAD: this.tags.TBODY,
    TFOOT: this.tags.TBODY,
    TH:    this.tags.TD
  });
}).call(Element._insertionTranslations);

Element.Methods.Simulated = {
  hasAttribute: function(element, attribute) {
    attribute = Element._attributeTranslations.has[attribute] || attribute;
    var node = $(element).getAttributeNode(attribute);
    return node && node.specified;
  }
};

Element.Methods.ByTag = {};

Object.extend(Element, Element.Methods);

if (!Prototype.BrowserFeatures.ElementExtensions && document.createElement('div').__proto__) {
    window.HTMLElement = {};
  window.HTMLElement.prototype = document.createElement('div').__proto__;
  Prototype.BrowserFeatures.ElementExtensions = true;
}

Element.extend = (function() {
    if (Prototype.BrowserFeatures.SpecificElementExtensions) return Prototype.K;

    var Methods = {},
        ByTag = Element.Methods.ByTag;

  var extend = Object.extend(function(element) {
        if (!element || element._extendedByPrototype || element.nodeType != 1 || element == window) return element;

    var methods = Object.clone(Methods),
            tagName = element.tagName,
            property, value;

        /* extend methods for specific tags */
    if (ByTag[tagName]) Object.extend(methods, ByTag[tagName]);

    for (property in methods) {
      value = methods[property];
            if (Object.isFunction(value) && !(property in element)) element[property] = value.methodize();
    }

    element._extendedByPrototype = Prototype.emptyFunction;
    return element;

  }, {
        refresh: function() { /* extend methods for all tags (Safari doesn't need this) */
      if (!Prototype.BrowserFeatures.ElementExtensions) {
        Object.extend(Methods, Element.Methods);
        Object.extend(Methods, Element.Methods.Simulated);
      }
    }
  });

  extend.refresh();
  return extend;
})();

Element.hasAttribute = function(element, attribute) {
  if (element.hasAttribute) return element.hasAttribute(attribute);
  return Element.Methods.Simulated.hasAttribute(element, attribute);
};

Element.addMethods = function(methods) {
    var F = Prototype.BrowserFeatures,
        T = Element.Methods.ByTag;

  if (!methods) {
    Object.extend(Form, Form.Methods);
    Object.extend(Form.Element, Form.Element.Methods);
    Object.extend(Element.Methods.ByTag, {
            'FORM': Object.clone(Form.Methods),
            'INPUT': Object.clone(Form.Element.Methods),
            'SELECT': Object.clone(Form.Element.Methods),
            'TEXTAREA': Object.clone(Form.Element.Methods)
    });
  }

  if (arguments.length == 2) {
    var tagName = methods;
    methods = arguments[1];
  }

    if (!tagName) Object.extend(Element.Methods, methods || {});
  else {
    if (Object.isArray(tagName)) tagName.each(extend);
    else extend(tagName);
  }

  function extend(tagName) {
    tagName = tagName.toUpperCase();
        if (!Element.Methods.ByTag[tagName]) Element.Methods.ByTag[tagName] = {};
    Object.extend(Element.Methods.ByTag[tagName], methods);
  }

  function copy(methods, destination, onlyIfAbsent) {
    onlyIfAbsent = onlyIfAbsent || false;
    for (var property in methods) {
      var value = methods[property];
      if (!Object.isFunction(value)) continue;
            if (!onlyIfAbsent || !(property in destination)) destination[property] = value.methodize();
    }
  }

  function findDOMClass(tagName) {
    var klass;
    var trans = {
            'OPTGROUP': 'OptGroup',
            'TEXTAREA': 'TextArea',
            'P': 'Paragraph',
            'FIELDSET': 'FieldSet',
            'UL': 'UList',
            'OL': 'OList',
            'DL': 'DList',
            'DIR': 'Directory',
            'H1': 'Heading',
            'H2': 'Heading',
            'H3': 'Heading',
            'H4': 'Heading',
            'H5': 'Heading',
            'H6': 'Heading',
            'Q': 'Quote',
            'INS': 'Mod',
            'DEL': 'Mod',
            'A': 'Anchor',
            'IMG': 'Image',
            'CAPTION': 'TableCaption',
            'COL': 'TableCol',
            'COLGROUP': 'TableCol',
            'THEAD': 'TableSection',
            'TFOOT': 'TableSection',
            'TBODY': 'TableSection',
            'TR': 'TableRow',
            'TH': 'TableCell',
            'TD': 'TableCell',
            'FRAMESET': 'FrameSet',
            'IFRAME': 'IFrame'
    };
    if (trans[tagName]) klass = 'HTML' + trans[tagName] + 'Element';
    if (window[klass]) return window[klass];
    klass = 'HTML' + tagName + 'Element';
    if (window[klass]) return window[klass];
    klass = 'HTML' + tagName.capitalize() + 'Element';
    if (window[klass]) return window[klass];

        window[klass] = {};
    window[klass].prototype = document.createElement(tagName).__proto__;
    return window[klass];
  }

  if (F.ElementExtensions) {
    copy(Element.Methods, HTMLElement.prototype);
    copy(Element.Methods.Simulated, HTMLElement.prototype, true);
  }

  if (F.SpecificElementExtensions) {
    for (var tag in Element.Methods.ByTag) {
      var klass = findDOMClass(tag);
      if (Object.isUndefined(klass)) continue;
      copy(T[tag], klass.prototype);
    }
  }

  Object.extend(Element, Element.Methods);
  delete Element.ByTag;

  if (Element.extend.refresh) Element.extend.refresh();
    Element.cache = {};
};

document.viewport = {
  getDimensions: function() {
        var dimensions = {};
    var B = Prototype.Browser;
    $w('width height').each(function(d) {
      var D = d.capitalize();
            dimensions[d] = (B.WebKit && !document.evaluate) ? self['inner' + D] : (B.Opera) ? document.body['client' + D] : document.documentElement['client' + D];
    });
    return dimensions;
  },

  getWidth: function() {
    return this.getDimensions().width;
  },

  getHeight: function() {
    return this.getDimensions().height;
  },

  getScrollOffsets: function() {
    return Element._returnOffset(
        window.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft, window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop);
  }
};
/** 
 * Portions of the Selector class are derived from Jack Slocum’s DomQuery,
 * part of YUI-Ext version 0.40, distributed under the terms of an MIT-style
 * license.  Please see http://www.yui-ext.com/ for more information. 
 */

var Selector = Class.create({
  initialize: function(expression) {
    this.expression = expression.strip();
    this.compileMatcher();
  },

  shouldUseXPath: function() {
    if (!Prototype.BrowserFeatures.XPath) return false;

    var e = this.expression;

        /* Safari 3 chokes on :*-of-type and :empty */
        if (Prototype.Browser.WebKit && (e.include('-of-type') || e.include(':empty'))) return false;

/* XPath can't do namespaced attributes, nor can it read
       the 'checked' property from DOM nodes */
        if ((/(\[[\w-]*?:|:checked)/).test(this.expression)) return false;

    return true;
  },

  compileMatcher: function() {
        if (this.shouldUseXPath()) return this.compileXPathMatcher();

        var e = this.expression,
            ps = Selector.patterns,
            h = Selector.handlers,
            c = Selector.criteria,
            le, p, m;

    if (Selector._cache[e]) {
      this.matcher = Selector._cache[e];
      return;
    }

        this.matcher = ['this.matcher = function(root) {',
                                'var r = root, h = Selector.handlers, c = false, n;'];

    while (e && le != e && (/\S/).test(e)) {
      le = e;
      for (var i in ps) {
        p = ps[i];
        if (m = e.match(p)) {
                    this.matcher.push(Object.isFunction(c[i]) ? c[i](m) : new Template(c[i]).evaluate(m));
          e = e.replace(m[0], '');
          break;
        }
      }
    }

        this.matcher.push('return h.unique(n);\n}');
    eval(this.matcher.join('\n'));
    Selector._cache[this.expression] = this.matcher;
  },

  compileXPathMatcher: function() {
        var e = this.expression,
            ps = Selector.patterns,
            x = Selector.xpath,
            le, m;

    if (Selector._cache[e]) {
            this.xpath = Selector._cache[e];
            return;
    }

    this.matcher = ['.//*'];
    while (e && le != e && (/\S/).test(e)) {
      le = e;
      for (var i in ps) {
        if (m = e.match(ps[i])) {
                    this.matcher.push(Object.isFunction(x[i]) ? x[i](m) : new Template(x[i]).evaluate(m));
          e = e.replace(m[0], '');
          break;
        }
      }
    }

    this.xpath = this.matcher.join('');
    Selector._cache[this.expression] = this.xpath;
  },

  findElements: function(root) {
    root = root || document;
    if (this.xpath) return document._getElementsByXPath(this.xpath, root);
    return this.matcher(root);
  },

  match: function(element) {
    this.tokens = [];

        var e = this.expression,
            ps = Selector.patterns,
            as = Selector.assertions;
    var le, p, m;

    while (e && le !== e && (/\S/).test(e)) {
      le = e;
      for (var i in ps) {
        p = ps[i];
        if (m = e.match(p)) {
/* use the Selector.assertions methods unless the selector
             is too complex. */
          if (as[i]) {
            this.tokens.push([i, Object.clone(m)]);
            e = e.replace(m[0], '');
          } else {
/* reluctantly do a document-wide search
               and look for a match in the array */
            return this.findElements(document).include(element);
          }
        }
      }
    }

        var match = true,
            name, matches;
    for (var i = 0, token; token = this.tokens[i]; i++) {
      name = token[0], matches = token[1];
      if (!Selector.assertions[name](element, matches)) {
                match = false;
                break;
      }
    }

    return match;
  },

  toString: function() {
    return this.expression;
  },

  inspect: function() {
        return '#<Selector:' + this.expression.inspect() + '>';
  }
});

Object.extend(Selector, {
    _cache: {},

  xpath: {
        descendant: '//*',
        child: '/*',
        adjacent: '/following-sibling::*[1]',
    laterSibling: '/following-sibling::*',
    tagName:      function(m) {
      if (m[1] == '*') return '';
            return "[local-name()='" + m[1].toLowerCase() + "' or local-name()='" + m[1].toUpperCase() + "']";
    },
    className:    "[contains(concat(' ', @class, ' '), ' #{1} ')]",
        id: '[@id="#{1}"]',
    attrPresence: function(m) {
      m[1] = m[1].toLowerCase();
            return new Template('[@#{1}]').evaluate(m);
    },
    attr: function(m) {
      m[1] = m[1].toLowerCase();
      m[3] = m[5] || m[6];
      return new Template(Selector.xpath.operators[m[2]]).evaluate(m);
    },
    pseudo: function(m) {
      var h = Selector.xpath.pseudos[m[1]];
      if (!h) return '';
      if (Object.isFunction(h)) return h(m);
      return new Template(Selector.xpath.pseudos[m[1]]).evaluate(m);
    },
    operators: {
      '=':  "[@#{1}='#{3}']",
      '!=': "[@#{1}!='#{3}']",
      '^=': "[starts-with(@#{1}, '#{3}')]",
      '$=': "[substring(@#{1}, (string-length(@#{1}) - string-length('#{3}') + 1))='#{3}']",
      '*=': "[contains(@#{1}, '#{3}')]",
      '~=': "[contains(concat(' ', @#{1}, ' '), ' #{3} ')]",
      '|=': "[contains(concat('-', @#{1}, '-'), '-#{3}-')]"
    },
    pseudos: {
      'first-child': '[not(preceding-sibling::*)]',
      'last-child':  '[not(following-sibling::*)]',
      'only-child':  '[not(preceding-sibling::* or following-sibling::*)]',
            'empty': '[count(*) = 0 and (count(text()) = 0 or translate(text(), " \t\r\n", "") = "")]',
            'checked': '[@checked]',
            'disabled': '[@disabled]',
            'enabled': '[not(@disabled)]',
      'not': function(m) {
                var e = m[6],
                    p = Selector.patterns,
                    x = Selector.xpath,
                    le, v;

        var exclusion = [];
        while (e && le != e && (/\S/).test(e)) {
          le = e;
          for (var i in p) {
            if (m = e.match(p[i])) {
              v = Object.isFunction(x[i]) ? x[i](m) : new Template(x[i]).evaluate(m);
                            exclusion.push('(' + v.substring(1, v.length - 1) + ')');
              e = e.replace(m[0], '');
              break;
            }
          }
        }
                return '[not(' + exclusion.join(' and ') + ')]';
      },
      'nth-child':      function(m) {
                return Selector.xpath.pseudos.nth('(count(./preceding-sibling::*) + 1) ', m);
      },
      'nth-last-child': function(m) {
                return Selector.xpath.pseudos.nth('(count(./following-sibling::*) + 1) ', m);
      },
      'nth-of-type':    function(m) {
                return Selector.xpath.pseudos.nth('position() ', m);
      },
      'nth-last-of-type': function(m) {
                return Selector.xpath.pseudos.nth('(last() + 1 - position()) ', m);
      },
      'first-of-type':  function(m) {
                m[6] = '1';
                return Selector.xpath.pseudos['nth-of-type'](m);
      },
      'last-of-type':   function(m) {
                m[6] = '1';
                return Selector.xpath.pseudos['nth-last-of-type'](m);
      },
      'only-of-type':   function(m) {
                var p = Selector.xpath.pseudos;
                return p['first-of-type'](m) + p['last-of-type'](m);
      },
      nth: function(fragment, m) {
                var mm, formula = m[6],
                    predicate;
        if (formula == 'even') formula = '2n+0';
        if (formula == 'odd')  formula = '2n+1';
                if (mm = formula.match(/^(\d+)$/)) /* digit only */
                return '[' + fragment + '= ' + mm[1] + ']';
                if (mm = formula.match(/^(-?\d*)?n(([+-])(\d+))?/)) { /* an+b */
                    if (mm[1] == '-') mm[1] = -1;
          var a = mm[1] ? Number(mm[1]) : 1;
          var b = mm[2] ? Number(mm[2]) : 0;
                    predicate = '[((#{fragment} - #{b}) mod #{a} = 0) and ' + '((#{fragment} - #{b}) div #{a} >= 0)]';
          return new Template(predicate).evaluate({
                        fragment: fragment,
                        a: a,
                        b: b
                    });
        }
      }
    }
  },

  criteria: {
    tagName:      'n = h.tagName(n, r, "#{1}", c);      c = false;',
    className:    'n = h.className(n, r, "#{1}", c);    c = false;',
    id:           'n = h.id(n, r, "#{1}", c);           c = false;',
    attrPresence: 'n = h.attrPresence(n, r, "#{1}", c); c = false;',
    attr: function(m) {
      m[3] = (m[5] || m[6]);
      return new Template('n = h.attr(n, r, "#{1}", "#{3}", "#{2}", c); c = false;').evaluate(m);
    },
    pseudo: function(m) {
      if (m[6]) m[6] = m[6].replace(/"/g, '\\"');
      return new Template('n = h.pseudo(n, "#{1}", "#{6}", r, c); c = false;').evaluate(m);
    },
    descendant:   'c = "descendant";',
    child:        'c = "child";',
    adjacent:     'c = "adjacent";',
    laterSibling: 'c = "laterSibling";'
  },

  patterns: {
/* combinators must be listed first
      (and descendant needs to be last combinator) */
    laterSibling: /^\s*~\s*/,
    child:        /^\s*>\s*/,
    adjacent:     /^\s*\+\s*/,
    descendant:   /^\s/,

        /* selectors follow */
    tagName:      /^\s*(\*|[\w\-]+)(\b|$)?/,
    id:           /^#([\w\-\*]+)(\b|$)/,
    className:    /^\.([\w\-\*]+)(\b|$)/,
        pseudo: /^:((first|last|nth|nth-last|only)(-child|-of-type)|empty|checked|(en|dis)abled|not)(\((.*?)\))?(\b|$|(?=\s|[:+~>]))/,
    attrPresence: /^\[([\w]+)\]/,
    attr:         /\[((?:[\w-]*:)?[\w-]+)\s*(?:([!^$*~|]?=)\s*((['"])([^\4]*?)\4|([^'"][^\]]*?)))?\]/
  },

    /* for Selector.match and Element#match */
  assertions: {
    tagName: function(element, matches) {
      return matches[1].toUpperCase() == element.tagName.toUpperCase();
    },

    className: function(element, matches) {
      return Element.hasClassName(element, matches[1]);
    },

    id: function(element, matches) {
      return element.id === matches[1];
    },

    attrPresence: function(element, matches) {
      return Element.hasAttribute(element, matches[1]);
    },

    attr: function(element, matches) {
      var nodeValue = Element.readAttribute(element, matches[1]);
      return nodeValue && Selector.operators[matches[2]](nodeValue, matches[5] || matches[6]);
    }
  },

  handlers: {
/* UTILITY FUNCTIONS
       joins two collections */
    concat: function(a, b) {
      for (var i = 0, node; node = b[i]; i++)
        a.push(node);
      return a;
    },

        /* marks an array of nodes for counting */
    mark: function(nodes) {
      var _true = Prototype.emptyFunction;
      for (var i = 0, node; node = nodes[i]; i++)
        node._countedByPrototype = _true;
      return nodes;
    },

    unmark: function(nodes) {
      for (var i = 0, node; node = nodes[i]; i++)
        node._countedByPrototype = undefined;
      return nodes;
    },

        /** 
         * mark each child node with its position (for nth calls)
         * 'ofType' flag indicates whether we're indexing for nth-of-type rather than nth-child 
         */
    index: function(parentNode, reverse, ofType) {
      parentNode._countedByPrototype = Prototype.emptyFunction;
      if (reverse) {
        for (var nodes = parentNode.childNodes, i = nodes.length - 1, j = 1; i >= 0; i--) {
          var node = nodes[i];
          if (node.nodeType == 1 && (!ofType || node._countedByPrototype)) node.nodeIndex = j++;
        }
      } else {
        for (var i = 0, j = 1, nodes = parentNode.childNodes; node = nodes[i]; i++)
          if (node.nodeType == 1 && (!ofType || node._countedByPrototype)) node.nodeIndex = j++;
      }
    },

        /* filters out duplicates and extends all nodes */
    unique: function(nodes) {
      if (nodes.length == 0) return nodes;
            var results = [],
                n;
      for (var i = 0, l = nodes.length; i < l; i++)
        if (!(n = nodes[i])._countedByPrototype) {
          n._countedByPrototype = Prototype.emptyFunction;
          results.push(Element.extend(n));
        }
      return Selector.handlers.unmark(results);
    },

        /* COMBINATOR FUNCTIONS */
    descendant: function(nodes) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        h.concat(results, node.getElementsByTagName('*'));
      return results;
    },

    child: function(nodes) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        for (var j = 0, child; child = node.childNodes[j]; j++)
          if (child.nodeType == 1 && child.tagName != '!') results.push(child);
      }
      return results;
    },

    adjacent: function(nodes) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        var next = this.nextElementSibling(node);
        if (next) results.push(next);
      }
      return results;
    },

    laterSibling: function(nodes) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        h.concat(results, Element.nextSiblings(node));
      return results;
    },

    nextElementSibling: function(node) {
      while (node = node.nextSibling)
	      if (node.nodeType == 1) return node;
      return null;
    },

    previousElementSibling: function(node) {
      while (node = node.previousSibling)
        if (node.nodeType == 1) return node;
      return null;
    },

        /* TOKEN FUNCTIONS */
    tagName: function(nodes, root, tagName, combinator) {
      var uTagName = tagName.toUpperCase();
            var results = [],
                h = Selector.handlers;
      if (nodes) {
                if (combinator) { /* fastlane for ordinary descendant combinators */
                    if (combinator == 'descendant') {
            for (var i = 0, node; node = nodes[i]; i++)
              h.concat(results, node.getElementsByTagName(tagName));
            return results;
          } else nodes = this[combinator](nodes);
                    if (tagName == '*') return nodes;
        }
        for (var i = 0, node; node = nodes[i]; i++)
          if (node.tagName.toUpperCase() === uTagName) results.push(node);
        return results;
      } else return root.getElementsByTagName(tagName);
    },

    id: function(nodes, root, id, combinator) {
            var targetNode = $(id),
                h = Selector.handlers;
      if (!targetNode) return [];
      if (!nodes && root == document) return [targetNode];
      if (nodes) {
        if (combinator) {
          if (combinator == 'child') {
            for (var i = 0, node; node = nodes[i]; i++)
              if (targetNode.parentNode == node) return [targetNode];
          } else if (combinator == 'descendant') {
            for (var i = 0, node; node = nodes[i]; i++)
              if (Element.descendantOf(targetNode, node)) return [targetNode];
          } else if (combinator == 'adjacent') {
            for (var i = 0, node; node = nodes[i]; i++)
                        if (Selector.handlers.previousElementSibling(targetNode) == node) return [targetNode];
          } else nodes = h[combinator](nodes);
        }
        for (var i = 0, node; node = nodes[i]; i++)
          if (node == targetNode) return [targetNode];
        return [];
      }
      return (targetNode && Element.descendantOf(targetNode, root)) ? [targetNode] : [];
    },

    className: function(nodes, root, className, combinator) {
      if (nodes && combinator) nodes = this[combinator](nodes);
      return Selector.handlers.byClassName(nodes, root, className);
    },

    byClassName: function(nodes, root, className) {
      if (!nodes) nodes = Selector.handlers.descendant([root]);
      var needle = ' ' + className + ' ';
      for (var i = 0, results = [], node, nodeClassName; node = nodes[i]; i++) {
        nodeClassName = node.className;
        if (nodeClassName.length == 0) continue;
                if (nodeClassName == className || (' ' + nodeClassName + ' ').include(needle)) results.push(node);
      }
      return results;
    },

    attrPresence: function(nodes, root, attr, combinator) {
            if (!nodes) nodes = root.getElementsByTagName('*');
      if (nodes && combinator) nodes = this[combinator](nodes);
      var results = [];
      for (var i = 0, node; node = nodes[i]; i++)
        if (Element.hasAttribute(node, attr)) results.push(node);
      return results;
    },

    attr: function(nodes, root, attr, value, operator, combinator) {
            if (!nodes) nodes = root.getElementsByTagName('*');
      if (nodes && combinator) nodes = this[combinator](nodes);
            var handler = Selector.operators[operator],
                results = [];
      for (var i = 0, node; node = nodes[i]; i++) {
        var nodeValue = Element.readAttribute(node, attr);
        if (nodeValue === null) continue;
        if (handler(nodeValue, value)) results.push(node);
      }
      return results;
    },

    pseudo: function(nodes, name, value, root, combinator) {
      if (nodes && combinator) nodes = this[combinator](nodes);
            if (!nodes) nodes = root.getElementsByTagName('*');
      return Selector.pseudos[name](nodes, value, root);
    }
  },

  pseudos: {
    'first-child': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        if (Selector.handlers.previousElementSibling(node)) continue;
          results.push(node);
      }
      return results;
    },
    'last-child': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        if (Selector.handlers.nextElementSibling(node)) continue;
          results.push(node);
      }
      return results;
    },
    'only-child': function(nodes, value, root) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
            if (!h.previousElementSibling(node) && !h.nextElementSibling(node)) results.push(node);
      return results;
    },
    'nth-child':        function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root);
    },
    'nth-last-child':   function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root, true);
    },
    'nth-of-type':      function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root, false, true);
    },
    'nth-last-of-type': function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root, true, true);
    },
    'first-of-type':    function(nodes, formula, root) {
            return Selector.pseudos.nth(nodes, '1', root, false, true);
    },
    'last-of-type':     function(nodes, formula, root) {
            return Selector.pseudos.nth(nodes, '1', root, true, true);
    },
    'only-of-type':     function(nodes, formula, root) {
      var p = Selector.pseudos;
      return p['last-of-type'](p['first-of-type'](nodes, formula, root), formula, root);
    },

        /* handles the an+b logic */
    getIndices: function(a, b, total) {
      if (a == 0) return b > 0 ? [b] : [];
      return $R(1, total).inject([], function(memo, i) {
        if (0 == (i - b) % a && (i - b) / a >= 0) memo.push(i);
        return memo;
      });
    },

        /* handles nth(-last)-child, nth(-last)-of-type, and (first|last)-of-type */
    nth: function(nodes, formula, root, reverse, ofType) {
      if (nodes.length == 0) return [];
      if (formula == 'even') formula = '2n+0';
      if (formula == 'odd')  formula = '2n+1';
            var h = Selector.handlers,
                results = [],
                indexed = [],
                m;
      h.mark(nodes);
      for (var i = 0, node; node = nodes[i]; i++) {
        if (!node.parentNode._countedByPrototype) {
          h.index(node.parentNode, reverse, ofType);
          indexed.push(node.parentNode);
        }
      }
            if (formula.match(/^\d+$/)) { /* just a number */
        formula = Number(formula);
        for (var i = 0, node; node = nodes[i]; i++)
          if (node.nodeIndex == formula) results.push(node);
            } else if (m = formula.match(/^(-?\d*)?n(([+-])(\d+))?/)) { /* an+b */
                if (m[1] == '-') m[1] = -1;
        var a = m[1] ? Number(m[1]) : 1;
        var b = m[2] ? Number(m[2]) : 0;
        var indices = Selector.pseudos.getIndices(a, b, nodes.length);
        for (var i = 0, node, l = indices.length; node = nodes[i]; i++) {
          for (var j = 0; j < l; j++)
            if (node.nodeIndex == indices[j]) results.push(node);
        }
      }
      h.unmark(nodes);
      h.unmark(indexed);
      return results;
    },

    'empty': function(nodes, value, root) {
            for (var i = 0, results = [], node; node = nodes[i]; i++) { /* IE treats comments as element nodes */
        if (node.tagName == '!' || (node.firstChild && !node.innerHTML.match(/^\s*$/))) continue;
        results.push(node);
      }
      return results;
    },

    'not': function(nodes, selector, root) {
            var h = Selector.handlers,
                selectorType, m;
      var exclusions = new Selector(selector).findElements(root);
      h.mark(exclusions);
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (!node._countedByPrototype) results.push(node);
      h.unmark(exclusions);
      return results;
    },

    'enabled': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (!node.disabled) results.push(node);
      return results;
    },

    'disabled': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (node.disabled) results.push(node);
      return results;
    },

    'checked': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (node.checked) results.push(node);
      return results;
    }
  },

  operators: {
        '=': function(nv, v) {
            return nv == v;
  },
        '!=': function(nv, v) {
            return nv != v;
        },
        '^=': function(nv, v) {
            return nv.startsWith(v);
        },
        '$=': function(nv, v) {
            return nv.endsWith(v);
        },
        '*=': function(nv, v) {
            return nv.include(v);
        },
        '~=': function(nv, v) {
            return (' ' + nv + ' ').include(' ' + v + ' ');
        },
        '|=': function(nv, v) {
            return ('-' + nv.toUpperCase() + '-').include('-' + v.toUpperCase() + '-');
        }
    },

  split: function(expression) {
    var expressions = [];
    expression.scan(/(([\w#:.~>+()\s-]+|\*|\[.*?\])+)\s*(,|$)/, function(m) {
      expressions.push(m[1].strip());
    });
    return expressions;
  },

  matchElements: function(elements, expression) {
        var matches = $$(expression),
            h = Selector.handlers;
    h.mark(matches);
    for (var i = 0, results = [], element; element = elements[i]; i++)
      if (element._countedByPrototype) results.push(element);
    h.unmark(matches);
    return results;
  },

  findElement: function(elements, expression, index) {
    if (Object.isNumber(expression)) {
            index = expression;
            expression = false;
    }
    return Selector.matchElements(elements, expression || '*')[index || 0];
  },

  findChildElements: function(element, expressions) {
    expressions = Selector.split(expressions.join(','));
        var results = [],
            h = Selector.handlers;
    for (var i = 0, l = expressions.length, selector; i < l; i++) {
      selector = new Selector(expressions[i].strip());
      h.concat(results, selector.findElements(element));
    }
    return (l > 1) ? h.unique(results) : results;
  }
});

if (Prototype.Browser.IE) {
  Object.extend(Selector.handlers, {
/* IE returns comment nodes on getElementsByTagName('*').
       Filter them out. */
    concat: function(a, b) {
      for (var i = 0, node; node = b[i]; i++)
            if (node.tagName !== '!') a.push(node);
      return a;
    },

        /* IE improperly serializes _countedByPrototype in (inner|outer)HTML. */
    unmark: function(nodes) {
      for (var i = 0, node; node = nodes[i]; i++)
        node.removeAttribute('_countedByPrototype');
      return nodes;
    }
  });
}

function $$() {
  return Selector.findChildElements(document, $A(arguments));
}
var Form = {
  reset: function(form) {
    $(form).reset();
    return form;
  },

  serializeElements: function(elements, options) {
        if (typeof options != 'object') options = {
            hash: !! options
        };
    else if (Object.isUndefined(options.hash)) options.hash = true;
        var key, value, submitted = false,
            submit = options.submit;

        var data = elements.inject({}, function(result, element) {
      if (!element.disabled && element.name) {
                key = element.name;
                value = $(element).getValue();
                if (value != null && (element.type != 'submit' || (!submitted && submit !== false && (!submit || key == submit) && (submitted = true)))) {
                    if (key in result) { /* a key is already present; construct an array of values */
            if (!Object.isArray(result[key])) result[key] = [result[key]];
            result[key].push(value);
          }
          else result[key] = value;
        }
      }
      return result;
    });

    return options.hash ? data : Object.toQueryString(data);
  }
};

Form.Methods = {
  serialize: function(form, options) {
    return Form.serializeElements(Form.getElements(form), options);
  },

  getElements: function(form) {
        return $A($(form).getElementsByTagName('*')).inject([], function(elements, child) {
            if (Form.Element.Serializers[child.tagName.toLowerCase()]) elements.push(Element.extend(child));
        return elements;
        });
  },

  getInputs: function(form, typeName, name) {
    form = $(form);
    var inputs = form.getElementsByTagName('input');

    if (!typeName && !name) return $A(inputs).map(Element.extend);

    for (var i = 0, matchingInputs = [], length = inputs.length; i < length; i++) {
      var input = inputs[i];
            if ((typeName && input.type != typeName) || (name && input.name != name)) continue;
      matchingInputs.push(Element.extend(input));
    }

    return matchingInputs;
  },

  disable: function(form) {
    form = $(form);
    Form.getElements(form).invoke('disable');
    return form;
  },

  enable: function(form) {
    form = $(form);
    Form.getElements(form).invoke('enable');
    return form;
  },

  findFirstElement: function(form) {
    var elements = $(form).getElements().findAll(function(element) {
      return 'hidden' != element.type && !element.disabled;
    });
    var firstByIndex = elements.findAll(function(element) {
      return element.hasAttribute('tabIndex') && element.tabIndex >= 0;
        }).sortBy(function(element) {
            return element.tabIndex;
        }).first();

    return firstByIndex ? firstByIndex : elements.find(function(element) {
      return ['input', 'select', 'textarea'].include(element.tagName.toLowerCase());
    });
  },

  focusFirstElement: function(form) {
    form = $(form);
    form.findFirstElement().activate();
    return form;
  },

  request: function(form, options) {
        form = $(form), options = Object.clone(options || {});

        var params = options.parameters,
            action = form.readAttribute('action') || '';
    if (action.blank()) action = window.location.href;
    options.parameters = form.serialize(true);

    if (params) {
      if (Object.isString(params)) params = params.toQueryParams();
      Object.extend(options.parameters, params);
    }

        if (form.hasAttribute('method') && !options.method) options.method = form.method;

    return new Ajax.Request(action, options);
  }
};

/*--------------------------------------------------------------------------*/

Form.Element = {
  focus: function(element) {
    $(element).focus();
    return element;
  },

  select: function(element) {
    $(element).select();
    return element;
  }
};

Form.Element.Methods = {
  serialize: function(element) {
    element = $(element);
    if (!element.disabled && element.name) {
      var value = element.getValue();
      if (value != undefined) {
                var pair = {};
        pair[element.name] = value;
        return Object.toQueryString(pair);
      }
    }
    return '';
  },

  getValue: function(element) {
    element = $(element);
    var method = element.tagName.toLowerCase();
    return Form.Element.Serializers[method](element);
  },

  setValue: function(element, value) {
    element = $(element);
    var method = element.tagName.toLowerCase();
    Form.Element.Serializers[method](element, value);
    return element;
  },

  clear: function(element) {
    $(element).value = '';
    return element;
  },

  present: function(element) {
    return $(element).value != '';
  },

  activate: function(element) {
    element = $(element);
    try {
      element.focus();
            if (element.select && (element.tagName.toLowerCase() != 'input' || !['button', 'reset', 'submit'].include(element.type))) element.select();
        } catch (e) {}
    return element;
  },

  disable: function(element) {
    element = $(element);
    element.blur();
    element.disabled = true;
    return element;
  },

  enable: function(element) {
    element = $(element);
    element.disabled = false;
    return element;
  }
};

/*--------------------------------------------------------------------------*/

var Field = Form.Element;
var $F = Form.Element.Methods.getValue;

/*--------------------------------------------------------------------------*/

Form.Element.Serializers = {
  input: function(element, value) {
    switch (element.type.toLowerCase()) {
      case 'checkbox':
      case 'radio':
        return Form.Element.Serializers.inputSelector(element, value);
      default:
        return Form.Element.Serializers.textarea(element, value);
    }
  },

  inputSelector: function(element, value) {
    if (Object.isUndefined(value)) return element.checked ? element.value : null;
        else element.checked = !! value;
  },

  textarea: function(element, value) {
    if (Object.isUndefined(value)) return element.value;
    else element.value = value;
  },

  select: function(element, index) {
        if (Object.isUndefined(index)) return this[element.type == 'select-one' ? 'selectOne' : 'selectMany'](element);
    else {
      var opt, value, single = !Object.isArray(index);
      for (var i = 0, length = element.length; i < length; i++) {
        opt = element.options[i];
        value = this.optionValue(opt);
        if (single) {
          if (value == index) {
            opt.selected = true;
            return;
          }
        }
        else opt.selected = index.include(value);
      }
    }
  },

  selectOne: function(element) {
    var index = element.selectedIndex;
    return index >= 0 ? this.optionValue(element.options[index]) : null;
  },

  selectMany: function(element) {
    var values, length = element.length;
    if (!length) return null;

    for (var i = 0, values = []; i < length; i++) {
      var opt = element.options[i];
      if (opt.selected) values.push(this.optionValue(opt));
    }
    return values;
  },

    optionValue: function(opt) { /* extend element because hasAttribute may not be native */
    return Element.extend(opt).hasAttribute('value') ? opt.value : opt.text;
  }
};

/*--------------------------------------------------------------------------*/

Abstract.TimedObserver = Class.create(PeriodicalExecuter, {
  initialize: function($super, element, frequency, callback) {
    $super(callback, frequency);
    this.element   = $(element);
    this.lastValue = this.getValue();
  },

  execute: function() {
    var value = this.getValue();
        if (Object.isString(this.lastValue) && Object.isString(value) ? this.lastValue != value : String(this.lastValue) != String(value)) {
      this.callback(this.element, value);
      this.lastValue = value;
    }
  }
});

Form.Element.Observer = Class.create(Abstract.TimedObserver, {
  getValue: function() {
    return Form.Element.getValue(this.element);
  }
});

Form.Observer = Class.create(Abstract.TimedObserver, {
  getValue: function() {
    return Form.serialize(this.element);
  }
});

/*--------------------------------------------------------------------------*/

Abstract.EventObserver = Class.create({
  initialize: function(element, callback) {
    this.element  = $(element);
    this.callback = callback;

    this.lastValue = this.getValue();
        if (this.element.tagName.toLowerCase() == 'form') this.registerFormCallbacks();
        else this.registerCallback(this.element);
  },

  onElementEvent: function() {
    var value = this.getValue();
    if (this.lastValue != value) {
      this.callback(this.element, value);
      this.lastValue = value;
    }
  },

  registerFormCallbacks: function() {
    Form.getElements(this.element).each(this.registerCallback, this);
  },

  registerCallback: function(element) {
    if (element.type) {
      switch (element.type.toLowerCase()) {
        case 'checkbox':
        case 'radio':
          Event.observe(element, 'click', this.onElementEvent.bind(this));
          break;
        default:
          Event.observe(element, 'change', this.onElementEvent.bind(this));
          break;
      }
    }
  }
});

Form.Element.EventObserver = Class.create(Abstract.EventObserver, {
  getValue: function() {
    return Form.Element.getValue(this.element);
  }
});

Form.EventObserver = Class.create(Abstract.EventObserver, {
  getValue: function() {
    return Form.serialize(this.element);
  }
});
if (!window.Event) var Event = {};

Object.extend(Event, {
  KEY_BACKSPACE: 8,
  KEY_TAB:       9,
  KEY_RETURN:   13,
  KEY_ESC:      27,
  KEY_LEFT:     37,
  KEY_UP:       38,
  KEY_RIGHT:    39,
  KEY_DOWN:     40,
  KEY_DELETE:   46,
  KEY_HOME:     36,
  KEY_END:      35,
  KEY_PAGEUP:   33,
  KEY_PAGEDOWN: 34,
  KEY_INSERT:   45,

    cache: {},

  relatedTarget: function(event) {
    var element;
        switch (event.type) {
        case 'mouseover':
            element = event.fromElement;
            break;
        case 'mouseout':
            element = event.toElement;
            break;
        default:
            return null;
    }
    return Element.extend(element);
  }
});

Event.Methods = (function() {
  var isButton;

  if (Prototype.Browser.IE) {
        var buttonMap = {
            0: 1,
            1: 4,
            2: 2
        };
    isButton = function(event, code) {
      return event.button == buttonMap[code];
    };

  } else if (Prototype.Browser.WebKit) {
    isButton = function(event, code) {
      switch (code) {
            case 0:
                return event.which == 1 && !event.metaKey;
            case 1:
                return event.which == 1 && event.metaKey;
            default:
                return false;
      }
    };

  } else {
    isButton = function(event, code) {
      return event.which ? (event.which === code + 1) : (event.button === code);
    };
  }

  return {
        isLeftClick: function(event) {
            return isButton(event, 0);
        },
        isMiddleClick: function(event) {
            return isButton(event, 1);
        },
        isRightClick: function(event) {
            return isButton(event, 2);
        },

    element: function(event) {
      var node = Event.extend(event).target;
      return Element.extend(node.nodeType == Node.TEXT_NODE ? node.parentNode : node);
    },

    findElement: function(event, expression) {
      var element = Event.element(event);
      if (!expression) return element;
      var elements = [element].concat(element.ancestors());
      return Selector.findElement(elements, expression, 0);
    },

    pointer: function(event) {
      return {
                x: event.pageX || (event.clientX + (document.documentElement.scrollLeft || document.body.scrollLeft)),
                y: event.pageY || (event.clientY + (document.documentElement.scrollTop || document.body.scrollTop))
      };
    },

        pointerX: function(event) {
            return Event.pointer(event).x;
        },
        pointerY: function(event) {
            return Event.pointer(event).y;
        },

    stop: function(event) {
      Event.extend(event);
      event.preventDefault();
      event.stopPropagation();
      event.stopped = true;
    }
  };
})();

Event.extend = (function() {
    var methods = Object.keys(Event.Methods).inject({}, function(m, name) {
    m[name] = Event.Methods[name].methodize();
    return m;
  });

  if (Prototype.Browser.IE) {
    Object.extend(methods, {
            stopPropagation: function() {
                this.cancelBubble = true;
            },
            preventDefault: function() {
                this.returnValue = false;
            },
            inspect: function() {
                return '[object Event]';
            }
    });

    return function(event) {
      if (!event) return false;
      if (event._extendedByPrototype) return event;

      event._extendedByPrototype = Prototype.emptyFunction;
      var pointer = Event.pointer(event);
      Object.extend(event, {
        target: event.srcElement,
        relatedTarget: Event.relatedTarget(event),
        pageX:  pointer.x,
        pageY:  pointer.y
      });
      return Object.extend(event, methods);
    };

  } else {
        Event.prototype = Event.prototype || document.createEvent('HTMLEvents').__proto__;
    Object.extend(Event.prototype, methods);
    return Prototype.K;
  }
})();

Object.extend(Event, (function() {
  var cache = Event.cache;

  function getEventID(element) {
    if (element._prototypeEventID) return element._prototypeEventID[0];
    arguments.callee.id = arguments.callee.id || 1;
    return element._prototypeEventID = [++arguments.callee.id];
  }

  function getDOMEventName(eventName) {
        if (eventName && eventName.include(':')) return 'dataavailable';
    return eventName;
  }

  function getCacheForID(id) {
        return cache[id] = cache[id] || {};
  }

  function getWrappersForEventName(id, eventName) {
    var c = getCacheForID(id);
    return c[eventName] = c[eventName] || [];
  }

  function createWrapper(element, eventName, handler) {
    var id = getEventID(element);
    var c = getWrappersForEventName(id, eventName);
        if (c.pluck('handler').include(handler)) return false;

    var wrapper = function(event) {
            if (!Event || !Event.extend || (event.eventName && event.eventName != eventName)) return false;

      Event.extend(event);
      handler.call(element, event);
    };

    wrapper.handler = handler;
    c.push(wrapper);
    return wrapper;
  }

  function findWrapper(id, eventName, handler) {
    var c = getWrappersForEventName(id, eventName);
        return c.find(function(wrapper) {
            return wrapper.handler == handler;
        });
  }

  function destroyWrapper(id, eventName, handler) {
    var c = getCacheForID(id);
    if (!c[eventName]) return false;
    c[eventName] = c[eventName].without(findWrapper(id, eventName, handler));
  }

  function destroyCache() {
    for (var id in cache)
      for (var eventName in cache[id])
        cache[id][eventName] = null;
  }

  if (window.attachEvent) {
        window.attachEvent('onunload', destroyCache);
  }

  return {
    observe: function(element, eventName, handler) {
      element = $(element);
      var name = getDOMEventName(eventName);

      var wrapper = createWrapper(element, eventName, handler);
      if (!wrapper) return element;

      if (element.addEventListener) {
        element.addEventListener(name, wrapper, false);
      } else {
                element.attachEvent('on' + name, wrapper);
      }

      return element;
    },

    stopObserving: function(element, eventName, handler) {
      element = $(element);
            var id = getEventID(element),
                name = getDOMEventName(eventName);

      if (!handler && eventName) {
        getWrappersForEventName(id, eventName).each(function(wrapper) {
          element.stopObserving(eventName, wrapper.handler);
        });
        return element;

      } else if (!eventName) {
        Object.keys(getCacheForID(id)).each(function(eventName) {
          element.stopObserving(eventName);
        });
        return element;
      }

      var wrapper = findWrapper(id, eventName, handler);
      if (!wrapper) return element;

      if (element.removeEventListener) {
        element.removeEventListener(name, wrapper, false);
      } else {
                element.detachEvent('on' + name, wrapper);
      }

      destroyWrapper(id, eventName, handler);

      return element;
    },

    fire: function(element, eventName, memo) {
      element = $(element);
            if (element == document && document.createEvent && !element.dispatchEvent) element = document.documentElement;

      var event;
      if (document.createEvent) {
                event = document.createEvent('HTMLEvents');
                event.initEvent('dataavailable', true, true);
      } else {
        event = document.createEventObject();
                event.eventType = 'ondataavailable';
      }

      event.eventName = eventName;
            event.memo = memo || {};

      if (document.createEvent) {
        element.dispatchEvent(event);
      } else {
        element.fireEvent(event.eventType, event);
      }

      return Event.extend(event);
    }
  };
})());

Object.extend(Event, Event.Methods);

Element.addMethods({
  fire:          Event.fire,
  observe:       Event.observe,
  stopObserving: Event.stopObserving
});

Object.extend(document, {
  fire:          Element.Methods.fire.methodize(),
  observe:       Element.Methods.observe.methodize(),
  stopObserving: Element.Methods.stopObserving.methodize(),
  loaded:        false
});

(function() {
/* Support for the DOMContentLoaded event is based on work by Dan Webb,
     Matthias Miller, Dean Edwards and John Resig. */

  var timer;

  function fireContentLoadedEvent() {
    if (document.loaded) return;
    if (timer) window.clearInterval(timer);
        document.fire('dom:loaded');
    document.loaded = true;
  }

  if (document.addEventListener) {
    if (Prototype.Browser.WebKit) {
      timer = window.setInterval(function() {
                if (/loaded|complete/.test(document.readyState)) fireContentLoadedEvent();
      }, 0);

            Event.observe(window, 'load', fireContentLoadedEvent);

    } else {
            document.addEventListener('DOMContentLoaded', fireContentLoadedEvent, false);
    }

  } else {
        document.write('<script id=__onDOMContentLoaded defer src=//:><\/script>');
        $('__onDOMContentLoaded').onreadystatechange = function() {
            if (this.readyState == 'complete') {
        this.onreadystatechange = null;
        fireContentLoadedEvent();
      }
    };
  }
})(); /*------------------------------- DEPRECATED -------------------------------*/

Hash.toQueryString = Object.toQueryString;

var Toggle = {
    display: Element.toggle
};

Element.Methods.childOf = Element.Methods.descendantOf;

var Insertion = {
  Before: function(element, content) {
        return Element.insert(element, {
            before: content
        });
  },

  Top: function(element, content) {
        return Element.insert(element, {
            top: content
        });
  },

  Bottom: function(element, content) {
        return Element.insert(element, {
            bottom: content
        });
  },

  After: function(element, content) {
        return Element.insert(element, {
            after: content
        });
  }
};

var $continue = new Error('"throw $continue" is deprecated, use "return" instead');

/* This should be moved to script.aculo.us; notice the deprecated methods
   further below, that map to the newer Element methods. */
var Position = {
    /** 
     * set to true if needed, warning: firefox performance problems
     * NOT neeeded for page scrolling, only if draggable contained in
     * scrollable elements 
     * */
  includeScrollOffsets: false,

/* must be called before calling withinIncludingScrolloffset, every time the
     page is scrolled */
  prepare: function() {
        this.deltaX = window.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft || 0;
        this.deltaY = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop || 0;
  },

    /* caches x/y coordinate pair to use with overlap */
  within: function(element, x, y) {
        if (this.includeScrollOffsets) return this.withinIncludingScrolloffsets(element, x, y);
    this.xcomp = x;
    this.ycomp = y;
    this.offset = Element.cumulativeOffset(element);

        return (y >= this.offset[1] && y < this.offset[1] + element.offsetHeight && x >= this.offset[0] && x < this.offset[0] + element.offsetWidth);
  },

  withinIncludingScrolloffsets: function(element, x, y) {
    var offsetcache = Element.cumulativeScrollOffset(element);

    this.xcomp = x + offsetcache[0] - this.deltaX;
    this.ycomp = y + offsetcache[1] - this.deltaY;
    this.offset = Element.cumulativeOffset(element);

        return (this.ycomp >= this.offset[1] && this.ycomp < this.offset[1] + element.offsetHeight && this.xcomp >= this.offset[0] && this.xcomp < this.offset[0] + element.offsetWidth);
  },

    /* within must be called directly before */
  overlap: function(mode, element) {
    if (!mode) return 0;
        if (mode == 'vertical') return ((this.offset[1] + element.offsetHeight) - this.ycomp) / element.offsetHeight;
        if (mode == 'horizontal') return ((this.offset[0] + element.offsetWidth) - this.xcomp) / element.offsetWidth;
  },

    /* Deprecation layer -- use newer Element methods now (1.5.2). */

  cumulativeOffset: Element.Methods.cumulativeOffset,

  positionedOffset: Element.Methods.positionedOffset,

  absolutize: function(element) {
    Position.prepare();
    return Element.absolutize(element);
  },

  relativize: function(element) {
    Position.prepare();
    return Element.relativize(element);
  },

  realOffset: Element.Methods.cumulativeScrollOffset,

  offsetParent: Element.Methods.getOffsetParent,

  page: Element.Methods.viewportOffset,

  clone: function(source, target, options) {
        options = options || {};
    return Element.clonePosition(target, source, options);
  }
};

/*--------------------------------------------------------------------------*/

if (!document.getElementsByClassName) document.getElementsByClassName = function(instanceMethods) {
  function iter(name) {
        return name.blank() ? null : '[contains(concat(" ", @class, " "), " ' + name + ' ")]';
  }

  instanceMethods.getElementsByClassName = Prototype.BrowserFeatures.XPath ?
  function(element, className) {
    className = className.toString().strip();
    var cond = /\s/.test(className) ? $w(className).map(iter).join('') : iter(className);
    return cond ? document._getElementsByXPath('.//*' + cond, element) : [];
  } : function(element, className) {
    className = className.toString().strip();
        var elements = [],
            classNames = (/\s/.test(className) ? $w(className) : null);
    if (!classNames && !className) return elements;

    var nodes = $(element).getElementsByTagName('*');
    className = ' ' + className + ' ';

    for (var i = 0, child, cn; child = nodes[i]; i++) {
            if (child.className && (cn = ' ' + child.className + ' ') && (cn.include(className) || (classNames && classNames.all(function(name) {
            return !name.toString().blank() && cn.include(' ' + name + ' ');
            })))) elements.push(Element.extend(child));
    }
    return elements;
  };

  return function(className, parentElement) {
    return $(parentElement || document.body).getElementsByClassName(className);
  };
}(Element.Methods);

/*--------------------------------------------------------------------------*/

Element.ClassNames = Class.create();
Element.ClassNames.prototype = {
  initialize: function(element) {
    this.element = $(element);
  },

  _each: function(iterator) {
    this.element.className.split(/\s+/).select(function(name) {
      return name.length > 0;
    })._each(iterator);
  },

  set: function(className) {
    this.element.className = className;
  },

  add: function(classNameToAdd) {
    if (this.include(classNameToAdd)) return;
    this.set($A(this).concat(classNameToAdd).join(' '));
  },

  remove: function(classNameToRemove) {
    if (!this.include(classNameToRemove)) return;
    this.set($A(this).without(classNameToRemove).join(' '));
  },

  toString: function() {
    return $A(this).join(' ');
  }
};

Object.extend(Element.ClassNames.prototype, Enumerable);

/*--------------------------------------------------------------------------*/

Element.addMethods();