Security hole using sessions???...

Currently, I have a user coming from page1.php?id=5 clicking a link to go to page page2.php?id=5, and I am doing this using sessions as below:

Page 1:

session_start();
$_SESSION['id'] = $_GET['id'];

PHP:

Page 2:

session_start();
if (!isset ($_SESSION['id'])) {
// the user is not logged in. Go to page1.php or wherever
die("You came from the wrong page!");
} 

PHP:

This is working great when trying to access the URL by typing it directly into the browser. The problem is that if you successfully arrive at page2.php?id=5 and you change the ID in the address bar to id=6, id=7, etc, it will open up all the other users pages without an error message.

How do I prevent this? Thanks!

 

if (!isset ($_SESSION['id'])) {
die("You came from the wrong page!");
}

if($_SESSION['id'] != $_GET['id']) {
die("You are not the right guy to see this page !");
}