PHP Double Load

refer to the following img

http://img148.imageshack.us/img148/2333/phpload27rq.jpg

So PHPLoadButton #1 Loads PHP Load Box #1, that's fine and dandy

but how do I get it so that a PHPLoadButton #2 (which is nested in the loaded PHP Load Box #1) Loads PHPBox#2 (Which is ALSO nested inside PhpLoadBox #2)? I can't seem to load PhpLoadButton#2 without "unloading" PhPLoadButton#1 (Meaning that NavBar #1 and PHP LoadButton #1 dissappears)

Just so I understand-- Does phpLoadButton post the page to the server and come back with a formatted page, and then you want within that formatted page to post the page again, retain the first format, and add onto it based on what the second action is?