var showErrors = true;
var cache = new Array();

var xmlHttp = createXmlHttpRequestObject();

function createXmlHttpRequestObject() {

  var xmlHttp;
 
  try {
    xmlHttp = new XMLHttpRequest();
  }
  catch(e) {
    
    var XmlHttpVersions = new Array("MSXML2.XMLHTTP.6.0",
                                    "MSXML2.XMLHTTP.5.0",
                                    "MSXML2.XMLHTTP.4.0",
                                    "MSXML2.XMLHTTP.3.0",
                                    "MSXML2.XMLHTTP",
                                    "Microsoft.XMLHTTP");
   
    for (var i=0; i < XmlHttpVersions.length && !xmlHttp; i++) {
      try { 
        xmlHttp = new ActiveXObject(XmlHttpVersions[i]);
      } 
      catch (e) {} 
    }
  }
 
  if (!xmlHttp)
    displayError("Błąd podczas tworzenia obiektu XMLHttpRequest.");
  else 
    return xmlHttp;
}