private void ShowMarkerImport_Checked(object sender, RoutedEventArgs e)
{
if (markerImport == null)
{
markerImport = new MarkerImportWindow(airfield, this);
}
markerImport.Closed += MarkerImport_Closed;
markerImport.Show();
}
private void MarkerImport_Closed(object sender, EventArgs e)
{
markerImport = null;
}