I have the following code in my skin to print the contents of a page:

                <a href="#" onclick="window.print()">Print this Page</a>

 This is not going to be a trivial task as you, basically, trying to print contents of two browser windows at the same time. (Iframe is basically an instance of another browser window inside the first one)

Here is one search result I came up with on google: http://www.webdeveloper.com/forum/showthread.php?t=152798

Try this search http://www.google.com/search?rlz=1C1CHMI_en-USUS291US303&sourceid=chrome&ie=UTF-8&q=print+page+with+iframe+content for more.

 Unfortunately, nope. :(