Sec. 21.055.  RETALIATION.  An employer, labor union, or employment agency commits an unlawful employment practice if the employer, labor union, or employment agency retaliates or discriminates against a person who, under this chapter:
(1)  opposes a discriminatory practice;
(2)  makes or files a charge;
(3)  files a complaint;  or
(4)  testifies, assists, or participates in any manner in an investigation, proceeding, or hearing.
Acts 1993, 73rd Leg., ch. 269, Sec. 1, eff. Sept. 1, 1993.