function createRequest()
{
  var request;
  try
  {
    request = new XMLHttpRequest();
  }
  catch(tryMicrosoft)
  {
    try
    {
      request = new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch(tryOtherMicrosoft)
    {
      try
      {
        request = new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch(failed)
      {
        request= null;
      }
    }
  }
  if(request == null)
  {
    alert("Error creating request object!");
    return null
  }
  else
  {
    return request;
  }
}