[eluser]wh1tel1te[/eluser]
Sure, there is no reason why you can't handle the form validation in another method. In your index() method, just call the add_contact() method, which will return your errors. If you don't want people to be able to access "index.php/contacts/add_contact", you can add an underscore before the "add_contact" method to make it private, so it becomes "_add_contact()".