private void btnLoaiKhachHang_Click(object sender, RoutedEventArgs e)
 {
     if (ucLoaiKhachHang == null)
     {
         ucLoaiKhachHang = new UserControlLibrary.UCLoaiKhachHang(mTransit);
     }
     spNoiDung.Children.Clear();
     spNoiDung.Children.Add(ucLoaiKhachHang);
 }
 private void btnLoaiKhachHang_Click(object sender, RoutedEventArgs e)
 {
     if (ucLoaiKhachHang == null)
     {
         ucLoaiKhachHang = new UserControlLibrary.UCLoaiKhachHang(mTransit);
     }
     spNoiDung.Children.Clear();
     spNoiDung.Children.Add(ucLoaiKhachHang);
 }