session_destroy() question

[pld]

Hi all,

i am trying to log out a user from a site that authenticates and uses session variables to check if the user is allowed to view certain parts of the site.

I have a logout button, with the link leading to a single page that looks like this:

<?PHP
session_start();
header("Cache-control: private"); //IE6 FIX
$_SESSION = array();
session_destroy();

echo "You have been successfully logged out.";
?>

simple. but if the user uses the back button on his browser, he can still see everything he visited previously in the site...

am i just missing something simple? any help is certainly appreciated!

[okuto1973]

Try with this....

ini_set("session.cache_limiter","private, must-revalidate");

but don't know if works.......
or
header("Cache-control: private, must-revalidate"); //IE6 FIX