navHover = function() {

 var lis = document.getElementById("sidebar").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);