function createXMLHttpRequest(){
  try { return new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) {}
  try { return new ActiveXObject("Microsoft.XMLHTTP"); } catch (e) {}
  try { return new XMLHttpRequest(); } catch(e) {}
  alert("XMLHttpRequest not supported");
  return null;
}

function wallpapers(walp){
  var xhReq = createXMLHttpRequest();
  xhReq.open('GET', 'http://www.freewall.cz/wallpapers.php?id='+walp, true);
  xhReq.send(null);
}