Como faço para meu aplicativo receber o foco?

function ForceForegroundWindow(hwnd: THandle): Boolean;
const
  SPI_GETFOREGROUNDLOCKTIMEOUT = $2000;
  SPI_SETFOREGROUNDLOCKTIMEOUT = $2001;
var
  ForegroundThreadID: DWORD;
  ThisThreadID: DWORD;
  timeout: DWORD;
begin
  Application.Restore;
  if IsIconic(hwnd) then ShowWindow(hwnd, SW_RESTORE);

  if GetForegroundWindow = hwnd then Result := True
  else
  begin
    if ((Win32Platform = VER_PLATFORM_WIN32_NT) and (Win32MajorVersion > 4))
or
      ((Win32Platform = VER_PLATFORM_WIN32_WINDOWS) and
      ((Win32MajorVersion > 4) or ((Win32MajorVersion = 4) and
      (Win32MinorVersion > 0)))) then
    begin
      Result := False;
      ForegroundThreadID := GetWindowThreadProcessID(GetForegroundWindow,
nil);
      ThisThreadID := GetWindowThreadPRocessId(hwnd, nil);
      if AttachThreadInput(ThisThreadID, ForegroundThreadID, True) then
      begin
        BringWindowToTop(hwnd);
        SetForegroundWindow(hwnd);
        AttachThreadInput(ThisThreadID, ForegroundThreadID, False);
        Result := (GetForegroundWindow = hwnd);
      end;
      if not Result then
      begin
        SystemParametersInfo(SPI_GETFOREGROUNDLOCKTIMEOUT, 0, @timeout, 0);
        SystemParametersInfo(SPI_SETFOREGROUNDLOCKTIMEOUT, 0, TObject(0),
          SPIF_SENDCHANGE);
        BringWindowToTop(hwnd);
        SetForegroundWindow(hWnd);
        SystemParametersInfo(SPI_SETFOREGROUNDLOCKTIMEOUT, 0,
          TObject(timeout), SPIF_SENDCHANGE);
      end;
    end
    else
    begin
      BringWindowToTop(hwnd);
      SetForegroundWindow(hwnd);
    end;
    Result := (GetForegroundWindow = hwnd);
  end;
end;