Plain JavaScript radioClass Fn

radioclass.js

/* adapted from Ext Core radioClass */

function hasClass(el, cls) {
	return new RegExp("(^|\\s)" + cls + "(\\s|$)").test(el.className);
}
function addClass(el, cls) {
	if (!hasClass(el, cls)) {
		el.className += el.className ? " " + cls : cls;
	}
}
function removeClass(el, cls) {
	var rep = el.className.match(" " + cls) ? " " + cls : cls;
	el.className = el.className.replace(rep, "");
}

function radioClass(el, cls) {
	var siblings = el.parentNode.childNodes;
	for(var i=0; i<siblings.length; i++) {
		if(siblings[i].nodeType == 1) {
			removeClass(siblings[i], cls);
		}
	}
	addClass(el, cls);
}