<html>
  <head>
    <title>div3</title>
    <style type="text/css">
      div#CentradaSL { position:absolute;
                       border-width: 3;
                       border-style: dashed;
                       top:64px; right:64px; bottom:64px; left:64px; }
      p { color: #999999;
          text-indent: 25px;
          text-align: justify; }
    </style>

    <script> <!-- Para corregir errores de IE5 -->
      var MargenH = 80; var MargenV = 64;
      var ELM = (document.getElementById);
      var IE5 = ((ELM) &&
                 (navigator.userAgent.toLowerCase().indexOf('msie')!=-1) &&
                 !(window.opera));
      if (IE5)
        window.onresize=Dimensionar;

      function Dimensionar ()
      {
        document.getElementById('CentradaSL').style.width =
                (document.body.clientWidth-2*MargenH)+'px';
        document.getElementById('CentradaSL').style.height =
                (document.body.clientHeight-2*MargenV)+'px';
      }
    </script>

  </head>
<body bgcolor="#ffddee">
  <div id="CentradaSL">
    <p>... contenido de la caja...</p> </div>
</body>
</html>