function menuFix() {

    var sfEls = document.getElementById("nav").getElementsByTagName("li");

    for (var i=0; i<sfEls.length; i++) {

        sfEls[i].onmouseover=function() {

        this.className+=(this.className.length>0? " ": "") + "sfhover";

        }

        sfEls[i].onMouseDown=function() {

        this.className+=(this.className.length>0? " ": "") + "sfhover";

        }

        sfEls[i].onMouseUp=function() {

        this.className+=(this.className.length>0? " ": "") + "sfhover";

        }

        sfEls[i].onmouseout=function() {

        this.className=this.className.replace(new RegExp("( ?|^)sfhover\\b"), 

"");

        }

    }

}

window.onload=menuFix