In In re Marriage of Cutler (2000) 79 Cal.App.4th 460, the court held that a 1966 support order was enforceable in 1996 under Family Code section 4502 and that the lack of diligence defense was not available to the father under that statutory scheme. The court reasoned that although "the support judgment was issued in 1966, and never renewed, it was still extant at the time Family Code section 4502 became effective and at the time mother sought to enforce the support judgment." (Id. at p. 473.) It was "extant" because--although the judgment could not be enforced absent a prior court order--"it was still enforceable, albeit, at the discretion of the court." (Ibid.) Child support judgments are enforceable according to the statute in effect at the time enforcement is sought. (Id. at pp. 474, 477; see also Fogarty & Rasbeary (2000) 78 Cal.App.4th 1353 enforcing a child support order issued in 1976 pursuant to Family Code section 4502.) The court in Cutler said that eliminating the lack of diligence defense did not deprive the father of a substantive right because "any limitation on enforcement is purely procedural; it does not involve a substantive right." (Id. at p. 476.) The court also noted, "Changes in the law enlarging the time frame in which a child support order could be enforced as a matter of right, thus removing lack of diligence as a possible defense, have historically been applied in all instances where enforcement is sought after the statute has been enlarged." (Id. at p. 477.) "Further, civil statutes of limitations are designed to ' " 'promote justice by preventing surprises.' " ' A father can hardly claim to be surprised that there exists an outstanding judgment for child support; he was fully aware of the support order, his obligations thereunder, and his failure to fulfill those obligations. . . .. . . .Further, the custodial parent's interest in arrearages owed under a support judgment is not just statutory; the judgment is a vested property right protected by the California Constitution. " (Id. at pp. 476-477.)