private void button1_Copy12_Click(object sender, RoutedEventArgs e)
        {
            if (classes_listView.SelectedIndex == -1)
            {
                return;
            }

            _Classes.AddNewClass nc = new _Classes.AddNewClass();
            nc.EditedClass = ((Objects.CheckedObject)classes_listView.SelectedItem).Class;
            nc.ShowDialog();
        }
 private void button5_Click(object sender, RoutedEventArgs e)
 {
     _Classes.AddNewClass nc = new _Classes.AddNewClass();
     nc.ShowDialog();
 }