onload = function() {
    document.getElementById('leftbar').style.height = document.getElementById('rightbar').style.height = (document.getElementById('maincontent').offsetHeight + 10) + "px";
}

sfHover = function() {
    var sfEls = document.getElementById("nav").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);