public void AddContact() { try { var name = AddressUtility.checkName(Name); var email = AddressUtility.checkEmail(Email); var phone = AddressUtility.checkPhone(Phone); IContactModel cm = new ContactModel(); cm.Name = name; cm.Email = email; cm.Phone = phone; AddressBook.AddItemMenu(cm); EventAggregationProvider.EventAggregator.Publish(AddressBook.ListAllMenu()); MessageBox.Show(string.Format("Hello {0} {1} {2}!", Name, Email, Phone)); //Don't do this in real life :) TryClose(); } catch (AddressException ex) { MessageBox.Show(ex.Message); } }