function hasClass(ele, cls) {
	return ele.className.match(new RegExp('(\\s|^)' + cls + '(\\s|$)'));
}
function addClass(ele, cls) {
	if (!hasClass(ele, cls))
		ele.className += " " + cls;
}
function removeClass(ele, cls) {
	if (hasClass(ele, cls)) {
		var reg = new RegExp('(\\s|^)' + cls + '(\\s|$)');
		ele.className = ele.className.replace(reg, ' ');
	}
}