In Basaldua v. State, 558 S.W.2d 2, 5 (Tex. Crim. App. 1977), the court noted that the statute governing probation allows appeal only from a court's revocation of probation. See id. To complain of an error in the modification of probation, a defendant must file a writ of habeas corpus. See id. Case law has allowed complaints about a modification order on appeal only when violation of the modified order forms the basis of a subsequent revocation. See Elizondo v. State, 966 S.W.2d 671, 672 (Tex. App.-San Antonio 1998, no pet.).