When you specify variables after a PHP page like that, you're using the GET feature. You can access Page through this:
$_GET["Page"];
I would write the script you want like so:
<?php$page = $_GET["Page"];
$page = strtolower($page);
if(empty($page)) include("pages/home.php");
switch ($page) {
case "home":
include("pages/home.php");
case "links":
include("pages/links.php");
case "about":
include("pages/about.php");
default:
include("pages/error.php");
}
?>
However, I don't see the point in doing this unless you have stored all of your pages in a database, e.g. MSAccess or MySQL.
In the example above, it first checks whether the ?Page variable you send to the page is empty. If it is, it just includes the homepage. (So if you just go to index.php, it will send back the homepage.)
Then I check whether the variable is equal to the page names home, links and about (just some examples). If it is, it sends the browser back the page name in the /pages folder. For example, if you specified the about page it would actually send back /pages/about.php but it would look like it was index.php?Page=About.
If the page is an unknown page (e.g. sakdsjksd) then it sends back an error page to say so. You could link this to the home page instead but I think it's more professional to do it this way and you could include your site design on this page so it blends in anyway.
I hope this helps,
James