DWORD dwStyle = GetWindowLong(m_hWnd, GWL_STYLE);
  if(dwStyle & WS_CAPTION) {
    dwStyle &= ~WS_CAPTION;
  } else {
    dwStyle |= WS_CAPTION;
  }
  SetWindowLong(m_hWnd, GWL_STYLE, dwStyle);

  SetWindowPos(NULL, 0, 0, 0, 0,
        SWP_NOSIZE | SWP_NOMOVE | SWP_NOACTIVATE | SWP_NOZORDER | SWP_FRAMECHANGED);