title: Get height of iframe with external URL
body: <p>I have to include an external whitelabel site within an iframe on my page. There are numerous pages on the external site and they vary considerably in height.</p>
  
  <p>I need to adjust the height of my iframe to accommodate this.</p>
  
  <p>I can get the height of the first page loaded into the iframe (using PHP), but no way of getting subsequent page heights because no way of knowing what the url/location changes to in the iframe.</p>
  
  <p>As this is an external url in the iframe the usual security limitations apply, therefore ALL solutions must come from the parent frame. Solution must be workable on FF and IE at least.</p>
  
  <p>The only think I can think of is to test whether the scrollbars are visible on the iframe, but this is seemingly impossible in these circumstances.</p>
  
  <p>If anyone can prove me wrong, or has any other javascript/ajax/php cross-browser solution I'd love to hear it.</p>