Hiding a part of a form value

[th1chsn]

I have a form on my website where all usernames begin with "3635-". What I would like to do is create the form so that the user doesn't have to enter 3635- and doesn't even see it on the form. I just want them to enter everything after the 3635-.

Is there an easy way to do this?

TIA -- R

[tedster]

Can you add it on the server side when the form data is processed?

Otherwise I suppose you could also append those characters using javascript on the client side when the form is submitted, but that would not be nearly so sure an approach.