Preventing duplicate form submissions

Question

I came up with a technique to prevent duplicate form submission by going back/forward or refreshing the page. And I thought about duscussing it here, I already tested a samp

Answer 1

It looks like you are getting overly complicated with this. My favorite way, because it also prevents some session jacking hacks at the same time, is described here:

http://www.spotlesswebdesign.com/blog.php?id=11

It's simple and easy to impliment on any form. It uses a randomly generated page instance id to verify that the form submission received is identical to the last page served to that particular user.