private void comboBoxChooseChildUpdate_SelectionChanged(object sender, SelectionChangedEventArgs e)
 {
     try
     {
         if (comboBoxChooseChildUpdate.SelectedIndex != -1)
         {
             contract = bl.getContract((long)comboBoxChooseChildUpdate.SelectedValue);
             gridDetalisContract.DataContext = contract;
             mom = bl.getMother((long)comboBoxchooseMomUPdate.SelectedValue);
             gridHourMom.DataContext        = mom;
             buttonUpdateContract.IsEnabled = true;
             buttonUpdateMomhour.IsEnabled  = true;
         }
     }
     catch (Exception Ex)
     {
         MessageBox.Show(Ex.Message);
     }
 }