title: How to get height of entire document with JavaScript?
body: <p>Some documents I can't get the height of the document (to position something absolutely at the very bottom). Additionally, a padding-bottom on  seems to do nothing on these pages, but do on the pages where height will return. Case(s) in point:</p>
  
  <p><a href="http://fandango.com" rel="noreferrer">http://fandango.com</a><br>
  <a href="http://paperbackswap.com" rel="noreferrer">http://paperbackswap.com</a></p>
  
  <p>On Fandango<br>
  jQuery's <code>$(document).height();</code> returns correct value<br>
  <code>document.height</code> returns 0<br>
  <code>document.body.scrollHeight</code> returns 0</p>
  
  <p>On Paperback Swap:<br>
  jQuery's <code>$(document).height();</code> TypeError: <code>$(document)</code> is null<br>
  <code>document.height</code> returns an incorrect value<br>
  <code>document.body.scrollHeight</code> returns an incorrect value</p>
  
  <p>Note: I have browser level permissions, if there is some trick there.</p>