function clearClass()
{
	var menu = document.getElementById('menu_ul');
	var liArr = menu.getElementsByTagName('LI');
	if ('undefined' != liArr && liArr.length > 0)
	{
		for (var i = 0; i < liArr.length; i++)
		{
			liArr[i].className='';
		}
	}
}

var menu = document.getElementById('menu_ul');
var liArr = menu.getElementsByTagName('LI');
if ('undefined' != liArr && liArr.length > 0)
{
	for (var i = 0; i < liArr.length; i++)
	{
		var liEl = liArr[i];
		var aArr = liEl.getElementsByTagName('A');
		liEl.onclick = function (e) {
			clearClass();
			if ('undefined' != typeof(event))  event.cancelBubble  = true;
			this.className = "selected";
		}
		
	}
}