IServiceProvider with CAxWindow, how?

Hi,

I'm hosting a browser control with CAxWindow. It's a window with
WS_OVERLAPPEDWINDOW style. I needed to trap the javascript window.resizeBy
call and resize my popup window accordingly. Therefore I need to implement
IHTMLOMWindowServices. Here is what I come up with:

class CPopupWnd:
    public CWindowImpl<CPopupWnd, CAxWindow>,
    public IServiceProviderImpl<CPopupWnd>,
    public IHTMLOMWindowServices
{
public:
    BEGIN_SERVICE_MAP(CPopupWnd)
        SERVICE_ENTRY(SID_SHTMLOMWindowServices)
    END_SERVICE_MAP()

    void Init() // called after window creation
    {
        IObjectWithSite *pOWS = NULL;
        QueryHost(IID_IObjectWithSite, (void**)&pOWS);
        pOWS->SetSite((IServiceProvider*)this);
    }
    ......
};

This is not a COM class, so I put "return 0;" in both AddRef and Release. In
QueryInterface, I simply put "return S_OK;".

As I understand that CAxWindow implements IObjectWithSite. Therefore I can
just call SetSite and cast IServiceProvider* to redirect
CAxWindow's IServiceProvider call to my class.

But this isn't happening. Both QueryHost and SetSite returned S_OK. But my
IHTMLOMWindowServices implementation methods like resizeBy aren't getting
called.

How do I tell CAxWindow to use IServiceProvider and the service map defined
in my class?

Thanks in Advance,
He Shiming