public override void Render(float elapsedTime)
        {
            drawer2D.BeginDrawSprite();
            drawer2D.DrawSprite(backgroundSprite);
            drawer2D.EndDrawSprite();

            text.render();

            GuiMessage msg = gui.Update(elapsedTime, Input);

            // proceso el msg
            switch (msg.message)
            {
            case MessageType.WM_COMMAND:
                switch (msg.id)
                {
                case IDOK:
                    if (msg_box_app_exit)
                    {
                        Application.Exit();
                    }
                    if (msg_box_nueva_mision)
                    {
                        music.closeFile();
                        GameModel.ChangeLevel();
                    }
                    break;

                case IDCANCEL:
                    gui.EndDialog();
                    break;

                case ID_NUEVA_PARTIDA:
                    gui.MessageBox("Nueva Partida", "TGC Gui Demo");
                    msg_box_nueva_mision = true;
                    msg_box_app_exit     = false;
                    break;

                case ID_APP_EXIT:
                    gui.MessageBox("Desea Salir?", "TGC Gui Demo");
                    msg_box_app_exit     = true;
                    msg_box_nueva_mision = false;
                    break;

                case ID_CONTROLES:
                    gui.MessageBoxControles("Controles", "TGC Gui Demo");
                    break;
                }
                break;

            default:
                break;
            }

            gui.Render();
        }