function lywindow_width ()
{
  if (window.innerWidth)
  {
    return window.innerWidth;
  } 
  else if (document.body && document.body.offsetWidth) 
  {
    return document.body.offsetWidth;
  } 
  else 
  {
    return 0;
  }
}


img = new Image(); 
img.src = "/images/screen/" + screen.width + "x" + screen.height + "_" + lywindow_width() +".gif";
img.height = 1;
img.width = 1;