var Field = {  clear: function() {    for (var i = 0; i < arguments.length; i++)      $(arguments[i]).value = '';  },  focus: function(element) {    $(element).focus();  },    present: function() {    for (var i = 0; i < arguments.length; i++)      if ($(arguments[i]).value == '') return false;    return true;  },    select: function(element) {    $(element).select();  },     activate: function(element) {    element = $(element);    element.focus();    if (element.select)      element.select();  }}/*--------------------------------------------------------------------------*/var Form = {  serialize: function(form) {    var elements = Form.getElements($(form));    var queryComponents = new Array();        for (var i = 0; i < elements.length; i++) {      var queryComponent = Form.Element.serialize(elements[i]);      if (queryComponent)        queryComponents.push(queryComponent);    }        return queryComponents.join('&');  },    getElements: function(form) {    form = $(form);    var elements = new Array();    for (tagName in Form.Element.Serializers) {      var tagElements = form.getElementsByTagName(tagName);      for (var j = 0; j < tagElements.length; j++)        elements.push(tagElements[j]);    }    return elements;  },    getInputs: function(form, typeName, name) {    form = $(form);    var inputs = form.getElementsByTagName('input');        if (!typeName && !name)      return inputs;          var matchingInputs = new Array();    for (var i = 0; i < inputs.length; i++) {      var input = inputs[i];      if ((typeName && input.type != typeName) ||          (name && input.name != name))         continue;      matchingInputs.push(input);    }    return matchingInputs;  },  disable: function(form) {    var elements = Form.getElements(form);    for (var i = 0; i < elements.length; i++) {      var element = elements[i];      element.blur();      element.disabled = 'true';    }  },  enable: function(form) {    var elements = Form.getElements(form);    for (var i = 0; i < elements.length; i++) {      var element = elements[i];      element.disabled = '';    }  },  findFirstElement: function(form) {    return Form.getElements(form).find(function(element) {      return element.type != 'hidden' && !element.disabled &&        ['input', 'select', 'textarea'].include(element.tagName.toLowerCase());    });  },  focusFirstElement: function(form) {    Field.activate(Form.findFirstElement(form));  },  reset: function(form) {    $(form).reset();  }}Form.Element = {  serialize: function(element) {    element = $(element);    var method = element.tagName.toLowerCase();    var parameter = Form.Element.Serializers[method](element);        if (parameter) {      var key = encodeURIComponent(parameter[0]);      if (key.length == 0) return;            if (parameter[1].constructor != Array)        parameter[1] = [parameter[1]];            return parameter[1].map(function(value) {        return key + '=' + encodeURIComponent(value);      }).join('&');    }  },    getValue: function(element) {    element = $(element);    var method = element.tagName.toLowerCase();    var parameter = Form.Element.Serializers[method](element);        if (parameter)      return parameter[1];  }}Form.Element.Serializers = {  input: function(element) {    switch (element.type.toLowerCase()) {      case 'submit':      case 'hidden':      case 'password':      case 'text':        return Form.Element.Serializers.textarea(element);      case 'checkbox':        case 'radio':        return Form.Element.Serializers.inputSelector(element);    }    return false;  },  inputSelector: function(element) {    if (element.checked)      return [element.name, element.value];  },  textarea: function(element) {    return [element.name, element.value];  },    select: function(element) {    return Form.Element.Serializers[element.type == 'select-one' ?       'selectOne' : 'selectMany'](element);  },    selectOne: function(element) {    var value = '', opt, index = element.selectedIndex;    if (index >= 0) {      opt = element.options[index];      value = opt.value;      if (!value && !('value' in opt))        value = opt.text;    }    return [element.name, value];  },    selectMany: function(element) {    var value = new Array();    for (var i = 0; i < element.length; i++) {      var opt = element.options[i];      if (opt.selected) {        var optValue = opt.value;        if (!optValue && !('value' in opt))          optValue = opt.text;        value.push(optValue);      }    }    return [element.name, value];  }}/*--------------------------------------------------------------------------*/var $F = Form.Element.getValue;/*--------------------------------------------------------------------------*/Abstract.TimedObserver = function() {}Abstract.TimedObserver.prototype = {  initialize: function(element, frequency, callback) {    this.frequency = frequency;    this.element   = $(element);    this.callback  = callback;        this.lastValue = this.getValue();    this.registerCallback();  },    registerCallback: function() {    setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);  },    onTimerEvent: function() {    var value = this.getValue();    if (this.lastValue != value) {      this.callback(this.element, value);      this.lastValue = value;    }  }}Form.Element.Observer = Class.create();Form.Element.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {  getValue: function() {    return Form.Element.getValue(this.element);  }});Form.Observer = Class.create();Form.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {  getValue: function() {    return Form.serialize(this.element);  }});/*--------------------------------------------------------------------------*/Abstract.EventObserver = function() {}Abstract.EventObserver.prototype = {  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() {    var elements = Form.getElements(this.element);    for (var i = 0; i < elements.length; i++)      this.registerCallback(elements[i]);  },    registerCallback: function(element) {    if (element.type) {      switch (element.type.toLowerCase()) {        case 'checkbox':          case 'radio':          Event.observe(element, 'click', this.onElementEvent.bind(this));          break;        case 'password':        case 'text':        case 'textarea':        case 'select-one':        case 'select-multiple':          Event.observe(element, 'change', this.onElementEvent.bind(this));          break;      }    }      }}Form.Element.EventObserver = Class.create();Form.Element.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {  getValue: function() {    return Form.Element.getValue(this.element);  }});Form.EventObserver = Class.create();Form.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {  getValue: function() {    return Form.serialize(this.element);  }});