sfHover = function() {
     var sfEls = document.getElementById("mainnav").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);