 Dentro do <head> voc inserir o seguinte cdigo:
<script>
     var ie = /msie/i.test(navigator.userAgent);
     var ieBox = ie && (document.compatMode == null || document.compatMode == "BackCompat");

     function checkSize() {
       var canvasEl = ieBox ? document.body : document.documentElement;
       var w = window.innerWidth || canvasEl.clientWidth;
       var h = window.innerHeight || canvasEl.clientHeight;

       document.getElementById("teste").style.width = Math.max(0, w - 50) + "px";
       document.getElementById("teste").style.height = Math.max(0, h - 100) + "px";
     }

     window.onload = checkSize;
     window.onresize = checkSize;
   </script>

 e dentro do <bodY> voc inseri o cdigo:
<div id="teste">

Para evitar erros.

Dvidas? www.estudioinformatica.com.br 