private void Button_Click(object sender, RoutedEventArgs e)
        {
            if (!ERROR())
            {
                return;
            }
            test           = ((Test)DataContext);
            gif.Visibility = Visibility.Visible;
            new Thread(() =>

            {
                try
                {
                    bl.AddDrivingTest(test);

                    MessageBox.Show(test.ToString(), "Your test:");
                }
                catch (Exception m)
                {
                    // gif.Visibility = Visibility.Hidden;
                    MessageBox.Show(m.Message);
                }
                Dispatcher.Invoke(new Action(() =>
                {
                    try
                    {
                        gif.Visibility = Visibility.Hidden;
                        Close();
                    }
                    catch (Exception n)
                    {
                        MessageBox.Show(n.Message);
                    }
                }));
            }).Start();
        }