Vincent Mark Castillo, proceeding pro se and in forma pauperis, appeals the dismissal with prejudice of his 42 U.S.C. § 1983 complaint.

Castillo does not challenge the district court’s reasons for dismissing his claims against the various defendants related to the probation revocation proceedings. See Brinkmann v. Dallas County Deputy Sheriff Abner, 813 F.2d 744, 748 (5th Cir. 1987). He merely reiterates his assertion that he was never actually on probation and that the revocation proceeding was thus unlawful. Thus, Castillo has abandoned any challenge to the district court’s reasons for dismissing his claims concerning the probation revocation proceeding. See id.

Liberally construed, Castillo’s brief contains an assertion that the district court erred in dismissing his claims with prejudice after he sought leave to withdraw them until such time as the Heck ** condi *383 tions were met. Castillo has not shown that the district court erred in dismissing his claims with prejudice. Boyd v. Biggers, 31 F.3d 279, 282-84 (5th Cir. 1994).

To the extent that Castillo seeks habeas corpus relief with respect to his probation revocation proceeding, this appeal from the dismissal of his 42 U.S.C. § 1983 complaint is not the proper forum within which to seek such relief. Castillo’s appeal is without arguable merit and is frivolous. See Howard v. King, 707 F.2d 215, 219-20 (5th Cir. 1983). Because the appeal is frivolous, it is DISMISSED. See 5th Cir. R. 42.2.

Castillo is cautioned that future frivolous appeals filed by him or on his behalf will invite the imposition of sanctions. He is further cautioned to review any pending appeals to ensure that they do not raise arguments that are frivolous.

APPEAL DISMISSED AS FRIVOLOUS; SANCTION WARNING ISSUED.