private void delete_button_Click(object sender, RoutedEventArgs e) { if (deleteCB.SelectedItem == null) { MessageBox.Show("Please select an item to delete."); } else { FileReadWrite file = new FileReadWrite(); oldTask = student.TaskList[deleteCB.SelectedIndex]; student.DeleteTask(deleteCB.SelectedIndex); file.DeleteTaskToFile(student, oldTask); homeScreen hs = new homeScreen(student); this.Close(); hs.Show(); } }