This tutorial is even more vague than the last, so I strongly suggest you take the first tutorial before proceeding. This is basically the same as the first, only instead of the other pages being stored in text files, they are all stored in one document. Just past these three sections of code into your PHP document where you want the content to show up.

<!-- DEFUALT PAGE --!>
<?php
switch($mode) {
case "":
?>
This is the main page
<!-- END DEFUALT PAGE --!>

<!-- OTHER PAGES -->
<?php
break;
case "other":
?>
This is the other page
<!-- END OTHER PAGES -->

<!-- ENDING CODE -->
<?php
break;
}
?>
<!-- END ENDING CODE -->

The first section of code is just what will appear as default, that is when the page loads. The link to that would be:
?mode=
The second section of code there can be duplicated and you can change where is says "other" (right afer case) to whatever you'd like. However, that will affect the link that it coresponds with. So if it's set to:
case "other":
then the link to that would be:
?mode=other
And the last section is just to tell the browser to end the PHP navigation section. If you're still confused download the example