Append items into system menu

type
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
private
procedure WMSysCommand(var Msg: TWMSysCommand); message WM_SYSCOMMAND;
end;
...
const
ID_ABOUT = WM_USER + 1;
procedure TForm1.FormCreate(Sender: TObject);
var
hSysMenu: HMENU;
begin
hSysMenu := GetSystemMenu(Handle, false);
AppendMenu(hSysMenu, MF_SEPARATOR, 0, nil);
AppendMenu(hSysMenu, MF_STRING, ID_ABOUT, PChar(’&About...’));
end;

procedure TForm1.WMSysCommand(var Msg: TWMSysCommand);
begin
if Msg.CmdType = ID_ABOUT then
AboutForm.ShowModal
else
inherited;
end;