Session and validation

I had this thread going yesterday. Then basically think it reached a stalemate. I'm wondering has anyone setup forms using session variables and validation. Validation where the validating is done on the same page, and the redirected on success ? Maybe that is my problem , that session variables will get blown away when the validations are run in the same page. Shouldn't be right ? Let me ask though if I setup just a validation page, then on success I'm still doing a redirect (cause it's a multi page form) Or if I validate on the next page and there is an error, I redirect back, but then I also have to consider how the error is going to get printed on the first page. Anyone ? Stuart