How to notify site admin when user registers with a specific field checked My case site has student and teacher accounts (teacher/student radio buttons). When user registers as a teacher, admin has to be notified so that admin performs further checks to accept the account. 

How can I do this programmatically
You should be able to accomplish this easily using the Rules module:


Create a rule that triggers 'After saving a new account'
Add a condition that determines whether the value of the field is set to the teacher value (Using 'Data Comparison').
Add an action element to send a notification email (System > Send Mail).