sfHover = function() {
     var sfEls = document.getElementById("mainnav").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);