In your index.php page you should have only something like this:
<head><title>My Page</title></head>
<body>
<?
$page = $page."php";
include($page);
?>
</body>
then your url would be something like:
http://www.blabla.com/index.php?page=main
And you should have a main.php page that is the one that will be inserted into your index page.
Guillermo
