Want to display Warning: Page has Expired message

[Ghulam Rashid]

I want to display "Warning: Page has Expired" message after 2 mins of browser idle time. I have enabled following setting in my httpd config.

<IfModule mod_headers.c>
Header append Cache-Control: "private, max-age=120"
</IfModule>

I can see my web page is created in "Temporary Internet Files" with proper expired time i.e. mypage.jsp expires on 08/28/2007 10.23AM which was last access at 10.21 AM. But after waiting for 5 minutes when I am clicking on browser's back/forward button page is not expiring and even it displays the data from the cache.

Can someone suggest why page is not expiring? Waht I should do?

Thanks