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);