I have a form that needs to be spread across several pages, with each page being a separate category. On the final page the user can click "Submit" and all the form data is processed. I'm just curious as to what my options are as far as retaining the information entered on the pages. For instance, once page 1 is entered and the user goes to page 2 and enters some info and then decides to go back to page 1 because something was entered wrong, what are my options for re-populating all the form fields with the original info?

I was thinking that AJAX may be the answer. Otherwise I could only think that I'd have to enter all the values into $_SESSION variables, but that would be a major inconvenience on my part.

Any other suggestions?