var xmlhttpvar = new Array();
var xmlhttpvar_id = 0;

function getXMLHttpID()
{
  var i = 0;
  while (typeof xmlhttpvar[i] != "undefined")
    i++;
  return i;
}

function delXMLHttpID(xmlhttpvar_id)
{
  xmlhttpvar[xmlhttpvar_id].onreadystatechange = null;
  delete xmlhttpvar[xmlhttpvar_id];
  xmlhttpvar_id = 0;
}

function createRequest(xmlhttpvar_id)
{
  var request;
  try {
    request = new XMLHttpRequest();
  } catch (trymicrosoft) {
    try {
      request = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (othermicrosoft) {
      try {
        request = new ActiveXObject("Microsoft.XMLHTTP");
      } catch (failed) {
        request = false;
      }
    }
  }
  return request;
}