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

            GridMain.Children.Clear();

            txb_hotelName.Text = Login.hotelName;
            txb_title.Text     = "Nhận phòng";
            usc = new UC_CheckIn();
            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 "CheckIn":
                txb_title.Text = "Nhận phòng";
                usc            = new UC_CheckIn();
                GridMain.Children.Add(usc);
                break;

            case "CheckOut":
                txb_title.Text = "Trả phòng";
                usc            = new UC_CheckOut();
                GridMain.Children.Add(usc);
                break;

            case "Statistic":
                txb_title.Text = "Thống kê";
                usc            = new UC_Statistic();
                GridMain.Children.Add(usc);
                break;

            case "Report":
                txb_title.Text = "Báo cáo";
                usc            = new UC_Report();
                GridMain.Children.Add(usc);
                break;

            case "RoomStatus":
                txb_title.Text = "Trạng thái phòng";
                usc            = new ListRoom();
                GridMain.Children.Add(usc);
                break;

            case "SearchBill":
                txb_title.Text = "Tìm kiếm hóa đơn";
                usc            = new UC_FindBill();
                GridMain.Children.Add(usc);
                break;

            default:
                break;
            }
        }