private void Window_Closing(object sender, CancelEventArgs e)
        {
            if (!doNotShow)
            {
                MessageBoxResult mbr = MessageBox.Show("Are you sure you want to exit managing landmarks?",
                                                       "Exit Landmarks", MessageBoxButton.YesNo, MessageBoxImage.Question);
                if (mbr == MessageBoxResult.Yes)
                {
                    if (lw != null)
                    {
                        lw.Close();
                    }

                    if (notSaved)
                    {
                        MessageBoxResult mbr1 =
                            MessageBox.Show("Do you want to save all created changes before exiting?",
                                            "Save Landmarks", MessageBoxButton.YesNo, MessageBoxImage.Question);
                        if (mbr1 == MessageBoxResult.Yes)
                        {
                            m.setLandmarks(AvailableLandmarks);
                            m.copyLandmarks(ancestor.tempLandmarks);
                            m.setPlacedLandmarks();
                            MapWindow.notSaved = true;
                        }
                        else
                        {
                            m.setPlacedLandmarks();
                        }
                    }

                    if (cm != null)
                    {
                        cm.Close();
                    }
                }
                else
                {
                    e.Cancel = true;
                }
            }
        }