Hi I'd like to create custom page but Ez-pages is not enought for me... because that page has to be kind of new component that allow customers to create their own set of products from the products available in the shop and send it to admin via e-mail... aim of it is create a special offer for big customers... so

i want to create a page that will be a PHP/JS script and will bo opened with index.php?main_page=MY_PAGE

the question is:
1. where I have to add code that open the link index.php?main_page=MY_PAGE - I can't find any $_GET[] reader in main_page.php and index.php ;(
2. where to put the template of the script to be automatically opened by index.php

thanks for any help