Interaction logic for BillingWindow.xaml
Inheritance: System.Windows.Window
 private void Button_Click_6(object sender, RoutedEventArgs e)
 {
     BillingWindow bw = new BillingWindow();
     bw.ShowDialog();
 }
        private void Button_Click_6(object sender, RoutedEventArgs e)
        {
            BillingWindow bw = new BillingWindow();

            bw.ShowDialog();
        }