function popup(url, width, height)
{
  var width = (width == null) ? 600 : width;
  var height = (height == null) ? 350 : height;
  popupWindow = window.open(url, "rtsp_info",
                            "toolbar=0,directories=0,location=0,status=0,scrollbars=1,menubar=0,resizable=1,width=" +
                            width + ",height=" + height + "");
  
  moveToX = screen.width - width - 40;
  moveToY = screen.height / 4;
  
  popupWindow.moveTo(moveToX, moveToY);
  popupWindow.focus();
  
  return false;
}