if (window.innerWidth || window.innerHeight) { //opera Netscape 6 Netscape 4x Mozilla
    docwidth = window.innerWidth;
    docheight = window.innerHeight;
  } else if (document.body.clientWidth || document.body.clientHeight) { //IE Mozilla
    docwidth = document.body.clientWidth;
    docheight = document.body.clientHeight;
  }

  alert (docwidth+"*"+docheight);