WRIT GRANTED AND MADE PEREMPTORY: The trial court erred in failing to grant defendants' motion to vacate the order rendered April 20, 1988. The trial court's order dated April 20th effectively annulled the judgment dated March 9, 1987. The order was signed ex parte. An action for nullity of a judgment must be instituted as an ordinary proceeding and requires citation and service upon opposing parties. See Veillon v. Veillon, 517 So.2d 936 (La.App. 3 Cir. 1987) writ. den., 519 So.2d 105 (La. 1987). For these reasons it is hereby ordered that the order dated April 20, 1988 is reversed and set aside, and the case is remanded to the trial court for further proceedings consistent with this decision.