Sports Sign Up form

Question

Hi!
I've got a bit of a problem in that i'm trying to make a Sports Sign Up form....
This form needs to have, for example, 14 positions for a sports team, then people go to the form a fill in the position they want with their name and contact details. Once done, that position isn't available to anyone else. (hope that makes sense)
I'm having real trouble finding an online form I can use... any ideas will help my remaining hair stay intact!!
Thanks
Bob