@Override
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
        Client client = CH.getOptional(getDao(), Client.class, request.getParameter("client"));
        Collaborator collab = CH.getOptional(getDao(), Collaborator.class, request.getParameter("collaborator"));
        WorkType type = CH.getOptional(getDao(), WorkType.class, request.getParameter("type"));
        Lpu lpu = CH.getOptional(getDao(), Lpu.class, request.getParameter("lpu"));
        if (collab == null) {
            return IncomingParamsValidator.redirectTo("/operator/collaborator.htm", client, type, lpu, collab);
        }
        if ((lpu == null) && (type == null)) {