public Form1()
        {
            InitializeComponent();
            Timer t = new Timer();
            t.Interval = 3000;
            t.Tick += new EventHandler(t_Tick);
            t.Start();
        }
        void t_Tick(object sender, EventArgs e)
        {
            this.Close();
            // or this Process.GetCurrentProcess().CloseMainWindow();
        }