var OP = (navigator.userAgent.indexOf("Opera") != -1);
var IE = (navigator.userAgent.indexOf("MSIE") != -1) && !OP;
if (IE) {
    sfHover = function() {
        var sfEls = document.getElementById("nav1").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);
    }
}