Limiting where panes can dock

LRESULT CMainFrame::OnDockingPaneNotify(WPARAM wp, LPARAM lp)
{
    if (wp==XTP_DPN_ACTION)
    {
        XTP_DOCKINGPANE_ACTION* pAction = (XTP_DOCKINGPANE_ACTION*)lp;
        if (pAction->pPane->GetID()==IDR_TIMESCALE && pAction->action==xtpPaneActionDocking)
        {
            if (!pAction->pPane->IsHidden() && pAction->dockDirection!=xtpPaneDockTop && pAction->dockDirection!=xtpPaneDockBottom)
               pAction->bCancel=TRUE;
            else
               pAction->bCancel=FALSE;
            return 1;
        } 
    }
    return 0;
}