How to you save form data on a form submitted to itself?

I haven't touched cold fusion in 10 years so I'm a bit out of practice. I have a request from a user to save the form data on a form she submitted. I looked at the code and even made it just a simple form with no cf tags at all. And it still deletes the form data, is there a way to save it when the user clicks submit? I've tried adding the preservedata = "true" and that doens't help either. Any thoughts would be great.

Thanks

Laura