Form Data & History

Hi, I'm having some problems with form data disappearing and wondered if anyone has experience with this. On a secure server I'm using PHP to handle form data to collect personal information. If data is missing or incorrect, the user is alerted to 'go back'... but upon going back in history, all the data that was in the form is lost. This did not occur on my regular not-secure web server. Does anyone know what may cause this? Thank you! Steven J. Walker Walker Effects www.walkereffects.com steve@walkereffects.com