unit Unit1;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;
type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Memo1: TMemo;
    Label1: TLabel;
  private
    { Private declarations }
    procedure WndProc(var Message: TMessage); override;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.WndProc(var Message: TMessage);
begin

  if (Message.Msg = WM_LBUTTONDOWN) then
    begin
      Label1.Caption := 'LButtonDown'
    end;
  if (Message.Msg = WM_RBUTTONDOWN) then
    begin
      Label1.Caption := 'RButtonDown'
    end;
  inherited;
end;

end.