navHover = function() {
    var lis = document.getElementById("navmenu").getElementsByTagName("li");
    for (var i = 0; i < lis.length; i++) {
        lis[i].onmouseover = function() {
            this.className += " iehover";
        }
        lis[i].onmouseout = function() {
            this.className = this.className.replace(new RegExp(" iehover\\b"), "");
        }
    }
}
if (window.attachEvent) window.attachEvent("onload", navHover);