TRANSPARENT BACKGROUND

HDC hDCStatic = (HDC) wParam;
    HWND hWndCtrl = (HWND) lParam;
    
    UINT nID = ::GetDlgCtrlID( hWndCtrl );
    
    ::SetBkMode( hDCStatic, TRANSPARENT );
    
    switch( nID )
    {
    case IDC_GROUPBOX:        return (LRESULT)m_hBrCtl[0];
    case IDC_STATIC_TEXT:    return (LRESULT)m_hBrCtl[1];
    case IDC_RADIO1:        return (LRESULT)m_hBrCtl[2];
    case IDC_CHECK1:        return (LRESULT)m_hBrCtl[3];
    }