function menuFix() {
  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= "";
    }
  }
}

if (document.all){
window.attachEvent('onload',menuFix)//IEÖÐ
}
else{
window.addEventListener('load',menuFix,false);//firefox
}