function setHeight() {
  if (document.getElementById) {
    var o1 = document.getElementById('navcolumn');
    var o2 = document.getElementById('contentcolumn');
    if (o1.offsetHeight > o2.offsetHeight) {
      o2.style.height = o1.offsetHeight;
      document.getElementById('footer').style.top = o1.offsetHeight +
                                                    o1.offsetTop;
      document.getElementById('footer').style.visibility='visible';
    } else if (o2.offsetHeight > o1.offsetHeight) {
      o1.style.height = o2.offsetHeight;
      document.getElementById('footer').style.top = o2.offsetHeight +
                                                    o2.offsetTop;
      document.getElementById('footer').style.visibility='visible';
    }
  }
}