How to mark a HTML page as "Out of date"

Question

Hello!
I need a method to prevent the usage of the Back button in web browsers by my web users, and prohibit them to move back through old web pages. During this moving they should view "Page out of date" messages instead of old contents of previous pages.
How can I do it? Any ideas, links, samples are welcomed!
Thanks a lot!
Alex

Answer 1

One way to get unathorized access to a web application is the usage an old stolen application's web page. My task to prevent it. An old web page may contains some hidden fields with encrypted keys, or other protection data.
We should analize this info each time on the server side to distinguish an old (may be stolen) page, and the new (from a valid user) one.
But the usage of such kind protected pages is complex enough. To reduce this complexity I just want to mark all web pages as "expired". Then my users will see "Page out of date", when they try to get back to old pages in browsers. They cannot view "a valid old page" at all using browsers (they will get only the "Page out of date" page), and, concequently, they cannot send to my server requests using old links, and old protection keys. Any old data my be stolen data only using this way.
In this case the protection algorithm on the server side is simplified. Now I have only one valid page in my application (the latest page).
To expire the web page we should
1) create the HTTP header like this:
HTTP/1.1 200 OK
Date: Fri, 30 Oct 1998 13:19:41 GMT
Server: Apache/1.3.3 (Unix)
Cache-Control: max-age=3600, must-revalidate
Expires: Fri, 30 Oct 1998 14:19:41 GMT
Last-Modified: Mon, 29 Jun 1998 02:28:12 GMT
ETag: "3e86-410-3596fbbc"
Content-Length: 1040
Content-Type: text/html
2) provide on the server side some functionality to prevent just
regeneration.
My question was about samples, or ideas on this way to protect web apps for XE.
It may be very useful, because I cannot find a legal way to use HTTPS (SSL) with XE.
Thanks!
Alex