private void showUnitsButton_Click(object sender, RoutedEventArgs e)
 {
     UnitsGrid.Visibility  = Visibility.Visible;
     OrdersGrid.Visibility = Visibility.Collapsed;
     lstUnits = bl.GetHostingUnitsByHostId(int.Parse(tb_HostId.Text)).ToList();
     lstUnits.RemoveAll(x => x.Status == ActivityStatus.INACTIVE);
     UnitsViewList.ItemsSource = lstUnits;
     UnitsViewList.Items.Refresh();
 }