Radio Button Transparency Problem

Question

Hi, I want to make radio control transparent i tried with OnCtlColor it is not on radio control working but it is working on Static Text Control .when i put my control over a picture control with bitmap it is getting black.I am using MFC Dialog. here is the code

HBRUSH hbr = CDialog::OnCtlColor(pDC, pWnd, nCtlColor);

if(nCtlColor == CTLCOLOR_STATIC)

{

    hbr = (HBRUSH)::GetStockObject(HOLLOW_BRUSH);

    pDC->SetBkMode(TRANSPARENT);

}   

return hbr;