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);