How can a reservation system be incorporated into Zoho Sites ?

How can a reservation system be incorporated into Zoho Sites ?

I run a not for profit community cinema that typically has 60 visitors ate each of our monthly shows.  I wonder if it is possible to have a ticket reservation system attached to our Sites website and if so how.  Ideally this would accept PayPal payments but that is less important than enabling us to ensure we do not have more visitors than seats at one of our screenings.