C#

// Tags for DSP Function Radio Buttons
rbDSP1.Tag = new ControlFactory(ctlDSP1.Create);
rbDSP2.Tag = new ControlFactory(ctlDSP2.Create);
rbDSP3.Tag = new ControlFactory(ctlDSP3.Create);

 // On the main form
private void DisplayControl(object sender, System.EventArgs e)
{
RadioButton rb = sender as RadioButton;		// cast sender as RadioButton
     if (rb != null)  // Ensure successful casting
     {
	if (rb.Checked)	// Proceed if checked
	{
	   if (m_DSPControl != null)  
	   {	
		panelControl.Controls.Remove(m_DSPControl);
						m_DSPControl.Dispose();
	   }
					ControlFactory cf = rb.Tag as ControlFactory;
					m_DSPControl = cf();

if (m_DSPControl != null)
   panelControl.Controls.Add(m_DSPControl);
	}
    }
}

// In ctlDSP1 code
public static Control Create()
{
   return new ctlDSP1();
}