private void create(object sender, RoutedEventArgs e) { if (playListValidation.isAllFieldValidate() && ((PlayList)controller.complete(TextCommand.READ_PLAY_LIST_BY_NAME, playList.Name)) == null) { playList.UserId = user.Id; controller.complete(TextCommand.CREATE_PLAY_LIST, playList); back(sender, e); } else { MessageBox.Show("Wrong fields or play list already exist"); } }