“If the defendant has not been served, and does not appear, he may take advantage of the defect by affidavit of illegality; but if he has had his day in court, he can not go behind the judgment by an affidavit of illegality.” Civil Code (1910), § 5311. Patterson v. Georgia Gravel Co., 151 Ga. 813 (108 S. E. 237).

The affidavit of illegality in the instant case being based solely upon the ground that one of the jurors rendering the verdict upon which the judgment attacked is based was disqualified by reason of interest, and it not being alleged that the defendant had not been- served, or that he had not had “his day in court,” it was not error to dismiss the affidavit of illegality, on demurrer.

Judgment affirmed.