using System;
using System.Windows.Forms;
class MainForm: Form
{
  Timer timer = new Timer();
  Form modalForm = new Form();
  bool needToShow;
  public MainForm()
  {
    modalForm.Closed += new EventHandler(modalForm_Closed);
    Button btShowModal = new Button();
    btShowModal.Click += new EventHandler(btShowModal_Click);
    btShowModal.Parent = this;
    timer.Interval = 5000;
    timer.Tick += new EventHandler(timer_Tick);
    timer.Start();
    
  }
  static void Main()
  {
    Application.Run(new MainForm());
  }
  private void btShowModal_Click(object sender, EventArgs e)
  {
    modalForm.ShowDialog();
    needToShow = true;
  }
  private void timer_Tick(object sender, EventArgs e)
  {
    if (WindowState == FormWindowState.Normal)
      WindowState = FormWindowState.Minimized;
    else
    {
      WindowState = FormWindowState.Normal;
      if (needToShow)
        modalForm.ShowDialog();
    }
  }
  private void modalForm_Closed(object sender, EventArgs e)
  {
    needToShow = false;
  }
}