Hello,

I'm new to Apex, I'd like to know how can we have a user confirm Yes/No and save the record based on user input.

e.g.

User creates new contact and clicks save, if there is another contact with the same email address we'd want a confirmation box to pop up and say that this is a duplicate if they'd still like to continue.
If the user clicks yes, the contact is created/saved. If the user clicks no the record is not save.