question on OnNcPaint

hi,

I am trying to paint the border around the main frame black. This is
my current code
void CMainFrame::OnNcPaint()
{
    MSG &msg = AfxGetThreadState()->m_lastSentMsg;

    HRGN hRgn = (HRGN)msg.wParam;
    CRect rcWin; // window rect
    GetWindowRect(&rcWin);
    rcWin.OffsetRect(-rcWin.left, -rcWin.top);

    CWindowDC dcWin(this);
    CBrush brFrame(RGB(0,0,0));

    CRect finalRect;
    CRect clntRect;
    m_Client.GetWindowRect(clntRect);
    ScreenToClient(clntRect);

    CRect dockRect;
    m_Dock->GetWindowRect(dockRect);
    ScreenToClient(dockRect);
    ::UnionRect(finalRect,clntRect,dockRect);

    CRect toolRect;
    m_wndToolBar.GetWindowRect(toolRect);
    ScreenToClient(toolRect);
    ::UnionRect(finalRect,finalRect,toolRect);

    CRect statusRect;
    m_wndStatusBar.GetWindowRect(statusRect);
    ScreenToClient(statusRect);
    ::UnionRect(finalRect,finalRect,statusRect);

    HRGN hRgnTest2 = ::CreateRectRgnIndirect(finalRect);

    // window minus the client area
    HRGN hRgnNew = ::CreateRectRgnIndirect(&rcWin);
    HRGN hRgnAll = ::CreateRectRgnIndirect(&rcWin);

    if (msg.wParam > 1)
    {
        WPARAM savewp = msg.wParam;
        msg.wParam = (WPARAM)NULL;
        CombineRgn(hRgnNew, (HRGN)msg.wParam, hRgnTest2, RGN_DIFF);
        msg.wParam = (WPARAM)hRgnNew;
        CMDIFrameWnd::OnNcPaint();
        msg.wParam = savewp;
    }
    else
    {
        CombineRgn(hRgnNew, hRgnAll, hRgnTest2, RGN_DIFF);
        ::FillRgn(dcWin.m_hDC,hRgnNew,(HBRUSH)brFrame);
    }

    DeleteObject(hRgnAll);
    DeleteObject(hRgnNew);
    DeleteObject(hRgnTest2);

}
only the bottom and the right portion is getting painted black. The
caption and left side retains the window color.

any suggestions?

Regards
Mihir