public void InsertDinhKem(tblDinhKem dinhkem)
        {
            int dinhkemID = GetMaxIDDinhKem();

            dinhkem.DinhKemID = dinhkemID + 1;
            ABDH_DemoDataContext _libraryContext = new ABDH_DemoDataContext();

            _libraryContext.tblDinhKems.InsertOnSubmit(dinhkem);
            _libraryContext.SubmitChanges();
        }
        public void InsertTailieu(tblTaiLieu tailieu)
        {
            int tailieuID = GetMaxIDTailieu();

            tailieu.TaiLieuID = tailieuID + 1;
            ABDH_DemoDataContext _libraryContext = new ABDH_DemoDataContext();

            _libraryContext.tblTaiLieus.InsertOnSubmit(tailieu);
            _libraryContext.SubmitChanges();
            tblDinhKem dinhkem = new tblDinhKem();

            dinhkem.TaiLieuID = tailieuID;
            InsertDinhKem(dinhkem);
        }