BEGIN_MESSAGE_MAP(CXHitDlg, CDialog)
  ON_WM_NCHITTEST()
END_MESSAGE_MAP()

 afx_msg UINT OnNcHitTest(CPoint point);

UINT CXHitDlg::OnNcHitTest(CPoint point)
{
    UINT hit = CDialog::OnNcHitTest(point);
    if( hit == HTCLIENT )
    {
        return HTCAPTION;
    }
    return hit;
}