public void AddUpdateContact(string name, string category, string phoneNumber, string emailAddress) { if (dataModel.NameIsValid(name) == false) { mainView.DisplayErrorMessage("The name is invalid"); return; } if (dataModel.EmailAddressIsValid(emailAddress) == false) { mainView.DisplayErrorMessage("The email address is invalid"); return; } dataModel.AddUpdateContact(name, category, phoneNumber, emailAddress); mainView.AddUpdateContactInGrid(name, category, phoneNumber, emailAddress); }