[Janom]

В Form1:

Код:

uses Unit2;

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
Form1.Caption:='OK!!!!!!!!!!!!!!!!'
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
Form2.Show;
end;

В Form2:

Код:

uses Unit1;

{$R *.dfm}

procedure TForm2.FormShow(Sender: TObject);
begin
Button1.OnClick:=Form1.Button1.OnClick;
end;