Close windows application automatically

DateTime closeDownAt;
private void Activity()
   {
   closeDownAt = DateTime.Now.AddMinutes(30);
   }

private activityTimer_Tick(object sender, EventArgs e)
   {
   if (DateTime.Now >= closeDownAt)
      {
      Close();
      }
   }

Activity();
activityTimer.Interval = 30000;   //30 seconds in milliseconds
activityTimer.Tick += new EventHandler(activityTimer_Tick);
activityTimer.Start();

public partial class Form1 : Form
{
  public Form1()
  {
      InitializeComponent();
  }

  private int timeOutMs = 5000;

  private Timer timer = new Timer();

  private void Form1_Load(object sender, EventArgs e)
  {
      timer.Interval = timeOutMs;
      timer.Tick += Timer_Tick;

      Application.Idle += Application_Idle;
  }

  void Timer_Tick(object sender, EventArgs e)
  {
      Close();
  }

  void Application_Idle(object sender, EventArgs e)
  {
      if (timer.Enabled)
      {
          timer.Stop();
      }

      timer.Start();
  }
}

public partial class Form1 : Form
{
    private const int WM_LBUTTONDOWN = 0x0201;
    private const int WM_KEYDOWN     = 0x0100;

    private int timeout    = 20;
    private int inactivity = 0;
    private Thread watcher = null;
    private bool focused   = true;

    public delegate void UpdaterCallback();

    //--------------------------------------------------------------------------------
    // constructor
    public Form1()
    {
        InitializeComponent();

        // enumerate controls and add a previewkeydown handler for each one
        foreach (Control ctrl in this.Controls)
        {
            ctrl.PreviewKeyDown += new PreviewKeyDownEventHandler(ctrl_PreviewKeyDown);
        }
        watcher = new Thread(new ThreadStart(UpdateInactivity));
        watcher.Start();
    }

    //--------------------------------------------------------------------------------
    // Handle all keystrokes in all child controls
    void ctrl_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
    {
        ResetInactivity();
    }

    //--------------------------------------------------------------------------------
    // form gains focus
    private void Form1_Activated(object sender, EventArgs e)
    {
        focused = true;
        ResetInactivity();
    }

    //--------------------------------------------------------------------------------
    // form looses focus
    private void Form1_Deactivate(object sender, EventArgs e)
    {
        focused = false;
        ResetInactivity();
    }

    //--------------------------------------------------------------------------------
    // mouse move on the form
    private void Form1_MouseMove(object sender, MouseEventArgs e)
    {
        ResetInactivity();
    }

    //--------------------------------------------------------------------------------
    // resets inactivity indicator to 0
    private void ResetInactivity()
    {
        inactivity = 0;
    }

    //--------------------------------------------------------------------------------
    // Thread delegate that controls the inactivity indicator
    private void UpdateInactivity()
    {
        try
        {
            while (true)
            {
                Thread.Sleep(1000);
                if (focused)
                {
                    inactivity++;
                    if (progressBar1 != null)
                    {
                        progressBar1.Invoke(new UpdaterCallback(this.UpdateProgressBar));
                    }
                }
            }
        }
        catch (ThreadAbortException)
        {
        }
    }

    //--------------------------------------------------------------------------------
    // update the progress bar
    private void UpdateProgressBar()
    {
        // calculate the percentage, and display it
        progressBar1.Value = (int)(((double)inactivity / (double)timeout) * 100);
        // close the form if necessary
        if (inactivity >= timeout)
        {
            this.Close();
        }
    }

    //--------------------------------------------------------------------------------
    // Look for a keydown or left mouse button down not already handled by form events
    protected override void WndProc(ref Message m)     
    {         
        switch (m.WParam.ToInt64())
        {
            case WM_LBUTTONDOWN :
            case WM_KEYDOWN :
                inactivity = 0;
                break;
        }          
        base.WndProc(ref m);     
    }

    //--------------------------------------------------------------------------------
    // Abort the thread so we don't try to execute the delegate after its been 
    // destroyed
    private void Form1_FormClosing(object sender, FormClosingEventArgs e)
    {
        watcher.Abort();
    }      
}