function create_request()
{
  var X = null;
  try
  {
    X = new XMLHttpRequest();
  }
  catch (versuchmicrosoft)
  {
    try
    {
      X = new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch (anderesmicrosoft)
    {
      try
      {
        X = new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch (fehlschlag)
      {
        X = null;
      }
    }
  }
  if ( X == null )
  {
    alert("Error creating requestobject!");
  }
  return X;
}