(a) The rights, remedies, duties and penalties created by this Act are in addition to and not in substitution for any other rights, remedies, duties and penalties created by any other law.
     (b) Nothing in this Act shall be construed as invalidating any assignment of wages or benefits executed prior to January 1, 1984 (or July 1, 1985 with respect to invalidity under the Illinois Parentage Act of 1984) or any order for withholding served prior to July 1, 1997.