Allow only specific email address' domain to register through JQuery (preferably)

Question

I am trying to make registration form within which I want to register only with specific domains\' emails. For e.g. I want to register only the emails which are from the com

Answer 1

What if you have the input textbox only accept the first part of an email address and then have a select box that only has the email domains you want to allow for the user to select from?