sfHover = function() {
     var sfEls = document.getElementById("nav").getElementsByTagName("LI");
     for (var i=0; i<sfEls.length; i++) {
              sfEls[i].onmouseover=function() {
                      this.className+=" sfhover";
                      this.style.zIndex=8200;
              }         
              sfEls[i].onmouseout=function() {
                      this.className=this.className.replace(new RegExp(" sfhover\\b"), "");
              }
      }
} 

if (window.attachEvent) window.attachEvent("onload", sfHover);