function pobierz(co)
{
  if(co == 'data'){
    var url = "http://localhost/data.php";
  }
  else if(co == 'czas'){
    var url = "http://localhost/czas.php";
  }
  id = (new Date()).getTime();
  url += "?" + id;
  startGETRequest(url, onComplete, onEnd);
}
