var http = createRequestObject();

  function createRequestObject() {
    var ro;
    var browser = navigator.appName;

    if(browser == "Microsoft Internet Explorer") {
      ro = new ActiveXObject("Microsoft.XMLHTTP");
    } else {
      ro = new XMLHttpRequest();
    }
    return ro;
  }

    w = screen.width;
    h = screen.height;
    http.open('get', 'system/screen.php?w='+w+'&h='+h);
    http.send(null);