/*
 * copied from http://xavisys.com/2007/03/using-prototype-javascript-to-get-the-value-of-a-radio-group/
 */

/**
 * Returns the value of the selected radio button in the radio group, null if
 * none are selected, and false if the button group doesn't exist
 *
 * @param {radio Object} or {radio id} el
 * OR
 * @param {form Object} or {form id} el
 * @param {radio group name} radioGroup
 */
function $RF(el, radioGroup) {
	if($(el).tagName.toLowerCase() == 'input' && $(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;
}