[bulldog]

тема закрыта я разобрался

Код:

unit SDIMAIN;

interface

uses Windows, Classes, Graphics, Forms, Controls, Menus,
  Dialogs, StdCtrls, Buttons, ExtCtrls, ComCtrls, ImgList, StdActns,
  ActnList, ToolWin;

type
  TSDIAppForm = class(TForm)
    PageControl1: TPageControl;
    TabSheet1: TTabSheet;
    TabSheet2: TTabSheet;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  SDIAppForm: TSDIAppForm;

implementation

uses about, Unit1, Unit2, Unit3;

{$R *.dfm}

procedure TSDIAppForm.Button1Click(Sender: TObject);
begin
  application.createform(TForm1,Form1);
  if Form1.ShowModal=mrOk then
    begin
      //Some code
    end;
  Form1.Free;
end;

procedure TSDIAppForm.Button2Click(Sender: TObject);
begin
  application.createform(TForm2,Form2);
  if Form2.ShowModal=mrOk then
    begin
      //Some code
    end;
  Form2.Free;
end;

procedure TSDIAppForm.Button3Click(Sender: TObject);
begin
  application.createform(TForm3,Form3);
  if Form3.ShowModal=mrOk then
    begin
      //Some code
    end;
  Form3.Free;
end;
end.