session problems in PHP

[Anon]

Recently, i have write a website with PHP for people to find tutorial job online.
I have get trouble on PHP session:]

1.I have wrote a registration page .After the user submit its information,How can i use session to prevent people back or refresh.(I would like to show out a page that:The page is expired).How can i do this?

2.And then after the submition,i will send a e-mail to the user -email address in order to check his email vaildation and show out a link that let him to click and then to continute his registration.The question is how can i gerenate the link that the link is unique to each user and each click?

Thank you for help.

[deshpande]

Hi mt78,
For ur first query i suggest to paste this code in ur file:

$now = gmdate('D, d M Y H:i:s') . ' GMT';
header('Expires: ' . $now);
header('Last-Modified: ' . $now);
header('Cache-Control: no-store, no-cache, must-revalidate'); // HTTP/1.1
header('Cache-Control: pre-check=0, post-check=0, max-age=0'); // HTTP/1.1
header('Pragma: no-cache'); // HTTP/1.0
// Define the charset to be used
header('Content-Type: text/html; charset=' . charset);

now i m in hurry , i will get back to ur second quary in next session.

--Shashank..