style-id for own pages

[Highlandersepp]

first: my english is not so well

problem

i have much own pages, like this:
http://www.playerworlds.de/forum/orf09_anmeldung.php

my first code in php :

PHP Code:

<?php
define('STYLEID', 3);

now i need the hook (?) , that i can see the style-id 3 in this pages, but i see only the standard-style

i lost the code by db-crash, no backup , because i chanced before some days to own server and forgot it *gg*