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"), "");
          }
        }
      }