title: .body.scrollHeight doesn't work in Firefox
body: <p><code>.body.scrollHeight</code> does not work in Firefox.</p>
  
  <p>See: <a href="http://jsfiddle.net/gjrowe/X63KR/" rel="noreferrer">http://jsfiddle.net/gjrowe/X63KR/</a></p>
  
  <p>What is the correct syntax to use instead?</p>