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