function createXMLHttpRequest() {
  if (typeof XMLHttpRequest != 'undefined') {
    return new XMLHttpRequest();
  }
  try {
    return new ActiveXObject("Msxml2.XMLHTTP");
  } catch (e) {
    try {
      return new ActiveXObject("Microsoft.XMLHTTP");
    } catch (e) { }
  }
  return false;
}


function ajaxUpdate(url, id) {
  var xmlhttp = createXMLHttpRequest();
  if (xmlhttp) {
    xmlhttp.onreadystatechange = function() {
      if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
        document.getElementById(id).innerHTML = xmlhttp.responseText;
      }
    }
    xmlhttp.open("GET", url, true);
    xmlhttp.send(null);
  }
}