protected override bool BeforeSaveEntity(EntityInfo entityInfo)
        {
            // use beforesaveentity for security checks
            var entity = entityInfo.Entity;

            if (entity is tblTransactionImporterDiscounts)
            {
                return !IsSales;
            }

            if (entity is tblTransactions)
            {
                return BeforeSaveTransaction(entity as tblTransactions, entityInfo);
            }
            if (entity is tblEmployees)
            {
                // employee objects can only be changed by admin. basta
                if (!IsAdmin)
                    return false;
                // never allow admin to delete himself...
                if (((tblEmployees)entity).IDEmployee == UserId && entityInfo.EntityState == EntityState.Deleted)
                    return false;
                if (entityInfo.EntityState == EntityState.Deleted)
                    BeforeDeleteEmployees(entity as tblEmployees, entityInfo);

                return true;
            }

            throw new InvalidOperationException("Cannot save entity of unknown type");
        }