function initZindex() {
	var _id = document.getElementById('nav');
	if (_id) {setIndex(_id);}
	function setIndex(_x) {
		var lists = _x.getElementsByTagName("a");
		var list_len = lists.length;
		for (var j = 0; j < lists.length; j++) {
			lists[j].style.zIndex = list_len;
			list_len--;
		}
	}
}
if (window.addEventListener) window.addEventListener("load", initZindex, false);
else if (window.attachEvent) window.attachEvent("onload", initZindex);