[eluser]InsiteFX[/eluser]
If you want to prevent users from going backwards at all, you need to keep
track of where users are in the page sequence (e.g. SequencePage=1, SequencePage=2, etc.).
You can do that via cookies, or by setting a hidden form field value in each
page, or Session variables, or database tables. You keep a full list of the
pages on the server in an array. That way, when you receive a request, you
can check the user's current positional value. If the user is on page 2 and
requests page 1, for example, you simply do a server or client-side redirect
to the page you *want* them to see. In contrast, if the user is on page 2
and requests page 3, you allow the request to proceed normally. If the value
isn't present, you redirect to the beginning of the sequence.
