複数Formを一気に閉じる

class MyApplicationContext : ApplicationContext 
{
	private Form1 form1;
	private Form2 form2;

	private MyApplicationContext() 
	{
		form1 = new Form1();
		form1.Closed += new EventHandler(OnFormClosed);            
		form1.Show();
	}

	private void OnFormClosed(object sender, EventArgs e) 
	{
		if (sender is Form1) 
		{
			form2 = new Form2();
			form2.Closed += new EventHandler(OnFormClosed);
			form2.Show();
		}
		else if (sender is Form2) 
		{
			ExitThread();
		}

	}

	[STAThread]
	static void Main() 
	{
		MyApplicationContext context = new MyApplicationContext();
		Application.Run(context);
	}
}