Detect a click on the caption of a form

The following example will capture a click with the left button on the caption of the form . Put this declaration in the private of the form :

      Procedure WMNCLBUTTONDOWN ( Var Message : TMessage ) ;

         Message WM_NCLBUTTONDOWN ;

And the procedure in the implementation :

Procedure TForm1.WMNCLBUTTONDOWN ( Var Message : TMessage ) ;

Begin

   If Message.wParam = HTCAPTION Then Caption := 'CLICK' ;

   Message.Result := 0 ;

End ;