There are a few methods to ensure that a registration has closed in your event:

1. There is an option to receive an email once a Registration Type closes due to the maximum being reached or the deadline for accepting registrations passes.  To set this up do the following:
  1. Go to Communities > Special Events > Friends Asking Friends > Kintera Thon
  2. Hover over your event and click Website Info
  3. Click Fee Structure
  4. Scroll down to the "Registration Levels" section
  5. Click Edit next to the Registration Type
  6. Mark the checkbox for "Send me an email when the maximum number is reached or when the deadline passes."
  7. Click Save
  8. Go back to the Webinfo Checklist and click Publish This Event Now
2. Go to the front page of your event site and click on the Register link or button.  If registrations have closed you will receive a message stating that registration is closed.

3. You can go into the Website Features of your event and remove the option for Participant Registration.  This will close ALL registration on your event and not allow anyone to register for the event.