sfHover = function() {
    var sfEls = document.getElementById("nav").getElementsByTagName("LI");
    var prevEl = sfEls[0];
    var version = navigator.appVersion.indexOf("MSIE") >-1 ? parseFloat(navigator.appVersion.split("MSIE")[1]) : 0;
    var isIE7 = navigator.appName == "Microsoft Internet Explorer" && version >= 7;
    for (var i=0; i<sfEls.length; i++) {
        sfEls[i].onmouseover=function() {
        	if (isIE7) {
	       		prevEl.className=prevEl.className.replace(new RegExp(" sfhover\\b"), "");
	       	}
            this.className+=" sfhover";
        	if (isIE7) {
	            prevEl = this;
	        }
        }
        sfEls[i].onmouseout=function() {
            this.className=this.className.replace(new RegExp(" sfhover\\b"), "");
        }
    }
}
if (window.attachEvent) window.attachEvent("onload", sfHover);