Notify member when entering a duplicate event registration
I have a problem with members registering accidentally multiple times for an event. If a member registers but somehow messes up the PayPal payment, he will sometimes start the registration process over, not realizing that he is already registered. I know I could stop this by disallowing multiple registrations, but I have to allow them because I have many members (couples) who share an email address. So what I would like to see is a popup message notifying the registrant that he is already registered for the event and asking him to confirm that he wants to register again. This would pop up if the userid (email address) and the name are the same as a registration already on file.