31-1-307. Assignments invalid without notice to employer -- filing assignments. No assignment of wages or salary to a wage broker shall be valid or enforceable unless notice in writing of the same, accompanied by a copy of the assignment, shall be given to the employer within 1 day from the date of its execution. All assignments shall be filed in the office of the county clerk of the county where the assignor resides, and no assignment shall be valid unless so filed.