Кнопка "Свернуть"

unit Unit2;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs;
 
type
  TForm2 = class(TForm)
  private
    { Private declarations }
    procedure WMSysCommand(var Msg: TWMSysCommand); message WM_SYSCOMMAND;
  public
    { Public declarations }
  end;
 
var
  Form2: TForm2;
 
implementation
 
{$R *.dfm}
 
procedure TForm2.WMSysCommand(var Msg: TWMSysCommand);
begin
  if (Msg.CmdType and $FFF0) = SC_MINIMIZE then begin
    if Application.MainForm <> Self then
      Application.MainForm.WindowState := wsMinimized
    ;
  end;
  Inherited;
end;
 
end.

procedure TForm2.WMSysCommand(var Msg: TWMSysCommand);
var
  LastState : TWindowState;
begin
  if
    ((Msg.CmdType and $FFF0) = SC_MINIMIZE)
    and (Application.MainForm <> Self)
  then begin
    LastState := Self.WindowState;
    Application.MainForm.WindowState := wsMinimized;
    Inherited;
    Self.WindowState := LastState;
  end else begin
    Inherited;
  end;
end;

procedure TForm2.WMSysCommand(var Msg: TWMSysCommand);
var
  LastState : TWindowState;
begin
  if
    ((Msg.CmdType and $FFF0) = SC_MINIMIZE)
    and (Application.MainForm <> Self)
  then begin
    SendMessage(Application.MainForm.Handle, WM_SYSCOMMAND, Msg.CmdType, 0);
  end else begin
    Inherited;
  end;
end;

unit Unit5;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs;
 
type
  TForm5 = class(TForm)
  private
    { Private declarations }
  public
    { Public declarations }
  end;
...

unit Unit2;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs,
 
  UnitNew;
 
type
  TForm5 = class(TFormNew)
  private
    { Private declarations }
  public
    { Public declarations }
  end;
...