private void btn_Order_Begin(object sender, RoutedEventArgs e)
        {
            UserControl usc = null;

            GridMain.Children.Clear();
            usc = new CMPWindow();
            GridMain.Children.Add(usc);
        }
        private void ListViewMenu_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            UserControl usc = null;

            GridMain.Children.Clear();

            switch (((ListViewItem)((ListView)sender).SelectedItem).Name)
            {
            case "ItemOrder":
                usc = new CMPWindow();
                GridMain.Children.Add(usc);
                break;

            case "ItemExit":
                this.Close();
                break;

            default:
                break;
            }
        }