In re Marriage of Lusby (1998) 64 Cal. App. 4th 459 75 Cal. Rptr. 2d 263 concerned a postdissolution proceeding to adjudicate the former wife's request for certain add-on expenses to support the two minor children of the marriage. The trial court did recognize that family law judges retain "traditional discretionary authority to adjust child support orders in individual cases where fairness requires it." (Id. at p. 471.) However, ultimately the award was not based upon the court's equitable powers, but upon the statutory provisions of the Family Code. (Id. at pp. 473-475.) In addition, the question confronting the trial court was the modification of the level of support that would then be owed prospectively. It was nowhere discussed that the court had discretionary or equitable powers to alter or extinguish an amount of child support that had already been awarded and accrued, as would result in the instant case. The same can be said for Keith G. v. Suzanne H. (1998) 62 Cal. App. 4th 853 72 Cal. Rptr. 2d 525 (Keith G.) and Jackson v. Jackson (1975) 51 Cal. App. 3d 363 124 Cal. Rptr. 101. The Court of Appeal held that the trial court could: (1) give credit for past overpayment; (2) permit partial enforcement of, or quash a writ of execution against a parent in arrears who, during the period in question, had sole physical custody of the child; (3) take into consideration whether the parent had satisfied or otherwise discharged the support obligation. (Keith G., supra, 62 Cal. App. 4th at pp. 858-859; Jackson v. Jackson, supra, 51 Cal. App. 3d at p. 368.) The Court of Appeal did not hold that a trial court had "equitable discretion" to determine that the arrears were not required to be paid in any form. In fact, Keith G. holds that the trial court lacks jurisdiction to modify or terminate support that has already accrued. (Keith G., supra, 62 Cal. App. 4th at p. 858; Fam. Code, 3651, subd. (c); see also In re Marriage of Comer, supra, 14 Cal. 4th at pp. 541-542 (conc. opn. of Baxter, J.) judgment for child support is a vested property right involving due process considerations.) This interpretation of these cases comports with Family Code section 4502 that provides, in pertinent part, that "a judgment for child, family, or spousal support, including all lawful interest and penalties computed thereon, is enforceable until paid in full."