Occassionaly on a forms submission a user will hit the browser "back button" when he gets a confirmation form and change information and hit the submit button again. This causes duplicates. Thanks to you I have mastered the ability to post another form before submitting whcih solves most of my duplicate problems.
However on the final submission I would like the "page to expire" or preferably pull up a url with instructions of how to change your submitted information ..... I would like to prevent the form from coming back at all.