Dispaying form data on success page

Hi Everyone

I'm trying to create a personalised form success page by using the name field with the H1 tag, so something like <h1>Thank you {firstname}</h1>

I added /thank-you?fname={firstname} into the success redirect in the form options (thinking I could use perch_get()) but this doesn't pass on the data in the same way as the other form option boxes do.

Any pointers would be much appreciated.

Glen