What's wrong with this?

[Black_Apalachi]

It works the same way as the code you're using.. Besides the fact that it's much cleaner, and easier to use.

well are the red parts what are supposed to be edited with the appropriate file names?

[Dentafrice]

No.. you don't edit anything..

[RastaLulz]

well are the red parts what are supposed to be edited with the appropriate file names?

In the code Dentafrice posted, you don't edit a thing, you simply put it into your layout where you want your content, and use the url:
http://www.yourwebsite.com/index.php?page=(page)

It's better than having to edit the php script that you have everytime you have a new page.

[Black_Apalachi]

Oh OK, thanks. It just confused me not having to tell it what the files were etc .

[Dentafrice]

You get that from the variable.

[Black_Apalachi]

The only thing now is, when I go to http://localhost/site/ it shows the 404 error in the content area instead of my homepage content. It only shows the homepage once I click 'Home' on the nav.

Is there a default setting I can add to that code or something?

<?php

$page = $_GET["p"];
$page = "{$page}.php";

if(!file_exists($page)) {
    include "404.php";
} else {
    include $page;
}

?>

[Dentafrice]

<?php

$page = $_GET["p"];
$page = ($page == '') ? 'home' : $page;
$page = "{$page}.php";

if(!file_exists($page)) {
    include "404.php";
} else {
    include $page;
}

?>

[Black_Apalachi]

thank you sir .

[Dentafrice]

Edit the part that says home for the page you want.

[Black_Apalachi]

home is exactly what I want I'll owe you about 3 reps lol