function populateTage(id,xml) {
  alert(xml);
  var sel = document.getElementById(id);
  alert(sel);
  sel.disabled = false;
  var selected = sel.options[sel.selectedIndex].value;
  sel.innerHTML = '';
  var tage = xml.getElementsByTagName('tag');
  alert(tage.length);
  for (var i=0; i<tage.length; i++) {
      var datum = tage[i].getElementsByTagName('datum')[0].firstChild.nodeValue;
      var desc = tage[i].getElementsByTagName('desc')[0].firstChild.nodeValue;
      opt = new Option(desc, datum, false, (datum == selected));
      sel.options[sel.options.length] = opt;
  }
}