void CButtonWindow::_OnLButtonDown(POINT pt)
{
    pt;

    typeOfControl = DFCS_PUSHED;
    _StartCapture();
}
void CScrollBarWindow::_OnLButtonDown(POINT pt)
{
    _StartCapture();

    RECT rc = {0, 0, 0, 0};

    _pBtnUp->_GetClientRect(&rc);
    if (PtInRect(&rc, pt))
    {
        _pBtnUp->_OnLButtonDown(pt);
    }
    else
    {
        _pBtnDn->_GetClientRect(&rc);
        if (PtInRect(&rc, pt))
        {
            _pBtnDn->_OnLButtonDown(pt);
        }
    }
}