hoverlist = function() {
    if (document.all&&document.getElementById) {
        navRoot = document.getElementById("mainmenu");
        for (i=0; i<navRoot.childNodes.length; i++) {
            node = navRoot.childNodes[i];
            if (node.nodeName=="LI") {
                node.onmouseover=function() {
                    this.className+=" hover";
            	}
                node.onmouseout=function() {
                    this.className=this.className.replace(" hover", "");
                }
            }
        }
    }
}

window.onload = hoverlist;