Getting size of a page with iframes

Hi all,

I'm in need of getting the full size of a page with iframes.

The page itself doesn't say anything about the size with the iframes 
included, but should there exist a way to recover this information.

Example:
body -> width: 1000, height: 600
iframe -> width: 900, height: 2500

and I would expect width: 1000, heigt: 2500. But may exist an arbitrary 
number of frames.