I'm creating a booking form for a client. She'd like to restrict the form so that once all the seats are filled the form is no longer available, replaced by a "sold out" message.
I know the form can have a restricted number of submissions, but this doesn't help because most people will book more than one seat at a time. The number of form submissions won't match the number of seats.
Is there another way to restrict the number of form submissions via another numeric field?