function $RF(el, radioGroup)
{
	if($(el).type && $(el).type.toLowerCase() == "radio")
	{
		var radioGroup = $(el).name;
		var el = $(el).form;
	}
	else if ($(el).tagName.toLowerCase() != "form")
	{
		return false;
	}
	
	var checked = $(el).getInputs("radio", radioGroup).find(
		function(re) {return re.checked;}
	);
	return (checked) ? $F(checked) : null;
}

var RadioGroup = Class.create();
Object.extend(RadioGroup.prototype, {
  initialize: function(radioButtons, onChange) {
    if(radioButtons instanceof Array) {
      this.radioButtons = radioButtons.collect(function(rb) {
        return $(rb);
      });
    } else {
      this.radioButtons = $$(radioButtons);
    }
    this.radioButtons.each(function(rb) {
      rb.observe("click",this._click.bindAsEventListener(this));
    }.bind(this));
    this.selected = this.findSelected();
    this.onChange = onChange;
  },
  _click: function(event) {
    var element = Event.element(event);
    if(element.checked) {
      if(element != this.selected) {
        this.onChange(element, this.selected);
        this.selected = element;
      }
    } else {
      var currentSelected = this.findSelected();
      if(currentSelected) {
        this.onChange(currentSelected, this.selected);
        this.selected = currentSelected;
      }
    }
  },
  findSelected: function() {
    return this.radioButtons.find(function(rb) {
      return rb.checked;
    }.bind(this));
  }
});