This action is upon a judgment of a court of this Commonwealth which had jurisdiction of the subject and of the parties. It is regular in form, and is valid between the parties until vacated or reversed. The record of the judgment put in evidence shows that the parties agreed to refer the action, and that the action was referred, and that the referee was authorized to proceed ex parte if either party neglected to appear after due notice. Both parties appeared before the referee by their attorneys, and several hearings were had, after which the original attorney for the defendant withdrew his appearance, and, after due notice to the defendant, the referee proceeded ex parte and made his report, which was accepted and confirmed by the court, and judgment entered thereon. On these facts we do not intimate that by any proceedings the judgment can be vacated or reversed. It cannot be avoided by plea and proof in this action. See Brigham v. Burnham, 12 Allen, 97. Exceptions overruled.