dropDown = function() {
	var menus = document.getElementById("nav").getElementsByTagName("LI");
	for (var i=0; i<menus.length; i++) {
		menus[i].onmouseover=function() {
			this.className+=" mhover";
		}
		menus[i].onmouseout=function() {
			this.className=this.className.replace(new RegExp(" mhover\\b"), "");
		}
	}
}
if (window.attachEvent) window.attachEvent("onload", dropDown);