navHover = function() 
{ 
    var lis = document.getElementById("navmenu_Hawking").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);