[Typo3] Embedding php scripts

[Vlatko Šurlan]

Hi list people. I was trying to embed a result of a php script onto a 
page but failed to do so according to the example from mtb1. I have 
following situation:
page a contains a form, when form is submitted I want the result to be 
displayed on page b. So basically I have set the action="index.php?id=3" 
on the form. So I want to embed a php script on page with id 3 (page b) 
that will handle the request and output the result of that processing. 
Where can I find documentation on doing this? Thanks all in advance!