private void AddButton_Click(object sender, RoutedEventArgs e)
 {
     HostingUnit.Owner = Host.Person.Id;
     // HostingUnit.Area = (BO.Location)MyDictionary.TranslatStringeToEnum(areaComboBox.SelectedItem.ToString());
     try
     {
         HostingUnit.Key = bl.AddHostingUnit(HostingUnit);
         Host            = bl.GetHost(Host.Person.Id);
     }
     catch (DuplicateWaitObjectException exp)
     {
         MessageBox.Show(exp.Message);
         return;
     }
     catch (MissingMemberException ex)
     {
         MessageBox.Show(ex.Message);
         return;
     }
     MessageBox.Show("היחידה הוספה בהצלחה");
     LB.ItemsSource = Host.HostingUnits;
     LB.Items.Refresh();
     NavigationService.GoBack();
 }