Private Sub button1_Click(sender As Object, _
  e As EventArgs) Handles button1.Click
   ' If the CTRL key is pressed when the 
   ' control is clicked, hide the control. 
   If Control.ModifierKeys = Keys.Control Then
      CType(sender, Control).Hide()
   End If
End Sub

private void button1_Click(object sender, System.EventArgs e)
{
   /* If the CTRL key is pressed when the 
      * control is clicked, hide the control. */
   if(Control.ModifierKeys == Keys.Control)
   {
      ((Control)sender).Hide();
   }
}

private:
   void button1_Click( Object^ sender, System::EventArgs^ /*e*/ )
   {
      /* If the CTRL key is pressed when the
         * control is clicked, hide the control. */
      if ( Control::ModifierKeys == Keys::Control )
      {
         (dynamic_cast<Control^>(sender))->Hide();
      }
   }