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;
}