the checkout success page most likely wont have any thing posted to it.
the confirm page should be storing the checkout information in session variables, use the session variables instead of form elements.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.