private void bAddMetk_Click(object sender, EventArgs e)
        {
            AddMarker newForm = new AddMarker(scene);

            newForm.FormClosed += Marker_FormClosed;
            newForm.Owner       = this;
            newForm.ShowDialog();
        }
 private void bEditMetk_Click(object sender, EventArgs e)
 {
     if (lbMetk.SelectedItem != null)
     {
         AddMarker newForm = new AddMarker(scene, lbMetk.SelectedItem as Marker);
         newForm.FormClosed += Marker_FormClosed;
         newForm.Owner       = this;
         newForm.ShowDialog();
     }
 }