In Ex parte Slavin, 412 S.W.2d 43 (Tex. 1967), the divorce decree provided that the relator "pay the sum of $ 150.00 per month for the care, support and maintenance of the three minor children until said children attain the age of eighteen years . . . ." Id. at 44. The relator argued that the decree became ambiguous after one of the children turned eighteen. The relator paid $ 150 until one year after the eldest child turned eighteen, and then he reduced the payment proportionately to $ 100 for the two children still younger than eighteen. Id. While acknowledging the relator's interpretation, the Supreme Court noted that the decree was subject to another interpretation that would support the contempt order. Under that construction, the decree ordered the relator to pay support in the fixed monthly sum of $ 150 until the youngest of the three children reached the age of eighteen. Id. By such a construction, the relator would continue to pay $ 150 to the two children beneath the age of eighteen, and when the second child reached that age, the sum would continue until the youngest child reached eighteen. Id. The Court determined that the ambiguity of the support order rendered it unenforceable by contempt because it could not be readily understood. Id.