private Timer t = new Timer();
        void  Event_Trigger(object sender, EventArgs e)
        {               
            t.Interval = 4000;
            t.Tick +=new EventHandler(t_Tick);
           ShowNotificationForm();
            t.Start();
           
            
        }
        void t_Tick(object sender, EventArgs e)
        {
           CloseNotificationForm();
            t.Stop();
            
t.Dispose();           
        }
        
       private void ShowNotificationForm()
        {
             //do or show something
        }
       private void CloseNotificationForm()
        {
             //End your work here
        }