var onprogress = false;

function show(sort)
{
  if(onprogress){
    alert("Trwa przetwarzanie danych.\nSpróbuj za chwilę.");
    return;
  }
  onprogress = true;
  var url = "http://localhost/dane.php?sort=" + sort;
  url = encodeURI(url);
  startGETRequest(url, onComplete, onEnd);
}

function onComplete(responseText, responseXML)
{
  var dataDiv = document.getElementById("dataDiv");
  dataDiv.innerHTML = responseText;
}

function onEnd()
{
  onprogress = false;
}
