How do I hide the waitlist option?

When a class reaches its max enrollment the system automatically shows that the class is full in the online registration screen and shows a link to the parent to let them add the student to the wait list.  If you do not want this option for your classes you can disable it.  

Go to Magic > Online Registration > Settings tab and check this box then Save. This will prevent parents from adding students to the waitlist from the Parent Portal.