title: iframe.document.body.scrollHeight is double the correct value
body: <p><code>&lt;iframe name="asdf" id="asdf" onload="change_height(this)" src="asdf.jsp" width="250" scrolling="no" frameborder="0"&gt;&lt;/iframe&gt;</code></p>
  
  <pre><code>        function change_height(iframe) {
              if (document.all) {
                  // IE.
                  ieheight = iframe.document.body.scrollHeight;
                  iframe.style.height = ieheight;
              } else {
                  // Firefox.
                  ffheight= iframe.contentDocument.body.offsetHeight;
                  iframe.style.height = ffheight+ 'px';
  
              }
          }
  </code></pre>
  
  <p>ieheight is twice the actual height when this runs in IE7; haven't tested on IE6.  It's the same value if I use <em>scrollHeight</em> or <em>offsetHeight</em>.  </p>
  
  <p>It's the correct height in Firefox.  </p>
  
  <p>Before I patch this by just dividing the IE value /2, what's the right way to do this?</p>