var Form = {
  serialize: function(form) {
    var elements = Form.getElements(form);
    var queryComponents = new Array();
    
    for (var i = 0; i < elements.length; i++) {
      if(!elements[i].disabled){
		var queryComponent = Form.Element.serialize(elements[i]);
		if (queryComponent)
			queryComponents.push(queryComponent);
	  }
    }
    
    return queryComponents.join('&');
  },
  
  getElements: function(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) {    
    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 = '';
    }
  },  

  reset: function(form) {
    form.reset();
  }
}

Form.Element = {
  serialize: function(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]];
      
      var queryComponents = new Array();
	  for (var i = 0; i < parameter[1].length; i++) {
		queryComponents.push(key + '=' + encodeURIComponent(parameter[1][i]));
	  }
	  return queryComponents.join('&');
    }
  },
  
  getValue: function(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];
  }
}