sfHover = function() {
    var navElement = document.getElementById("nav");
    if( navElement != null)
    {
	    var sfEls = document.getElementById("nav").getElementsByTagName("LI");
	    for (var i=0; i<sfEls.length; i++) {
		    sfEls[i].onmouseover=function() {
			    this.className+=" over";
		    }
		    sfEls[i].onmouseout=function() {
			    this.className=this.className.replace(new RegExp(" over\\b"), "");
		    }
	    }
	}
}
if (window.attachEvent) window.attachEvent("onload", sfHover);