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);