Right of suppliers or salaried workers of the contractor

Those who have worked for the contractor, or have supplied him the materials for the work, shall have no right to sue the owner of the work, except to the extent the latter is the debtor of the contractor. Where the owner of the work had made payment to the contractor before the scheduled date, the seller of the materials as well as the workers shall have right to sue the owner for the amount payable, up to the amount which was anticipated by the latter.