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