WTL : how to catch button msg

Hi,

I know it's not a WTL newsgroup but generally people writing MFC has
also a knwoledge of WTL.
I have a simple Dialog Class defined like this :

class CMainDlg : public CDialogImpl<CMainDlg>,
                    public CWinDataExchange<CMainDlg>
{
public:

    BEGIN_MSG_MAP(CMainDlg)
        MESSAGE_HANDLER(WM_INITDIALOG, OnInitDialog)
        COMMAND_ID_HANDLER(IDOK, OnCloseCmd)
        COMMAND_ID_HANDLER(IDCANCEL, OnCloseCmd)
         ALT_MSG_MAP(1)
         MSG_WM_SETCURSOR(OnUpdateBtn)
     END_MSG_MAP()

    enum { IDD = IDD_MAINDLG };

    CMainDlg::CMainDlg() :
    m_wndUpdateBtn(this, 1){}

    virtual BOOL PreTranslateMessage(MSG* pMsg)
    {
        return ::IsDialogMessage(m_hWnd, pMsg);
    }
    LRESULT OnInitDialog(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM
/*lParam*/, BOOL& bHandled)
    {
        return bHandled = FALSE;
    }

    LRESULT OnCloseCmd(WORD /*wNotifyCode*/, WORD wID, HWND /*hWndCtl*/,
BOOL& /*bHandled*/)
    {
        EndDialog(wID);
        return 0;
    }

    LRESULT OnUpdateBtn(HWND hwndCtrl, UINT uHitTest, UINT uMouseMsg)
    {
        ::MessageBox(NULL, _T("fdfsdf"), _T(""), 0);
        return 0;
    }

protected:
    CContainedWindow m_wndUpdateBtn;
};

But when i click on my Update Btn nothings happens.

Any idea ?