private void subMenu_Edit_Click(object sender, RoutedEventArgs e)
        {
            int     index   = this.L_MainList.SelectedIndex;
            NewDiag newDiag = new NewDiag();

            newDiag.SetTargetParam(this.L_MainList.Items[index] as Target, index);
            newDiag.Closed += new EventHandler(subMenu_Closed_Handler);
            newDiag.Show();
        }