if you have a look to www.info2000.biz/forum you will see an aspx page which contains a forum (see from word "Info2000 Forum" and below).
This forum is hosted on another web server which answers at this address forum.infoduemila.com
The integration is done using nothing more that iFrame following these directions: http://benalman.com/code/projects/jquery-postmessage/examples/iframe/
If you see at bottom of the page, the forum page is truncated so the request is to find a way to resize the height of parent iFrame depending of forum page: at least at form load, if you also can also resize the iframe periodically let's say each 500ms, it would be better (this because user can expand or collapse forum sections).
I spent a few of hours without getting good resuls: as you can see.
A piece of code or fixing actual one is requested: up to you which solution to follow: jquery, html or whatever.
If you need some information more feel free to contact me.