function getXMLHttpRequestObject()
{
  var wersjeMSXML = new Array(
    "MSXML2.XMLHTTP.6.0",
    "MSXML2.XMLHTTP.5.0",
    "MSXML2.XMLHTTP.4.0",
    "MSXML2.XMLHTTP.3.0",
    "MSXML2.XMLHTTP",
    "Microsoft.XMLHTTP"
  );

  try{
    return new XMLHttpRequest();
  }
  catch(e){
    for (var indeks in wersjeMSXML){
      try{
        return new ActiveXObject(wersjeMSXML[indeks]);
      }
      catch(e){
      }
    }
    return null;
  }
}

function startGETRequest(url, onComplete, onEnd)
{
  var XMLHttpRequestObject = getXMLHttpRequestObject();
  if(XMLHttpRequestObject){
    XMLHttpRequestObject.open("GET", url);
    XMLHttpRequestObject.onreadystatechange = function()
    {
      if (XMLHttpRequestObject.readyState == 4){
        if(XMLHttpRequestObject.status == 200){
          var responseXML = XMLHttpRequestObject.responseXML;
          var responseText = XMLHttpRequestObject.responseText;
          onComplete(responseText, responseXML);
        }
        delete XMLHttpRequestObject;
        XMLHttpRequestObject = null;
        onEnd();
      }
    }
    XMLHttpRequestObject.send(null);
  }
}

function startPOSTRequest(url, params, onComplete, onEnd)
{
  var XMLHttpRequestObject = getXMLHttpRequestObject();
  if(XMLHttpRequestObject){
    XMLHttpRequestObject.open("POST", url);
    XMLHttpRequestObject.setRequestHeader(
      'Content-Type', 'application/x-www-form-urlencoded');
    XMLHttpRequestObject.onreadystatechange = function()
    {
      if (XMLHttpRequestObject.readyState == 4){
        if(XMLHttpRequestObject.status == 200){
          var responseXML = XMLHttpRequestObject.responseXML;
          var responseText = XMLHttpRequestObject.responseText;
          onComplete(responseText, responseXML);
        }
        delete XMLHttpRequestObject;
        onEnd();
      }
    }
    XMLHttpRequestObject.send(params);
  }
}