[web] need a simple php script

You've just explained the hard part of all that. All you need to do is implement it, it should be difficult since you already have your design.
You can see an example in Thacmus, using the Source page in the thacmus section. Look at how Page works in main.php (look at Page::find()), how it's defined in page.php, and how it's handled in content.php.
Remember, that's just one implementation. There's plenty of others if you don't like one particular solution.

Well I used to use this one line of code when I used to do a lot of web design but I have forgotten how to do it, it basically looked like

if not defiend id then include home.php else include id.php
I dont know the syntax for php.

I just had a note pad with a few simple scripts I liked to use.

Hey,

if you are trying to extract the value of "id" out of the url this is how you would do it:

$id= $_GET['id'];

the item in '' should be equal to whatever you are looking to extract out of the url.

Hope this helps.

[edit]
The poster above has a better solution :D.

Can someone fix my syntax?
I know it looked exactly like this... in theory, the syntax is wrong.

The correct version is, like, two posts above yours... perhaps you should try to actually read the answers to your threads.

if (!isset($id))   require_once('home.php') else   require_once("$id.php");

I tried that and I get a blank white page.