When the plaintiff files an amended complaint that omits a defendant named in the prior complaint, the amendment is treated as a voluntary dismissal of the omitted defendant, without prejudice. Here, plaintiff’s third amended complaint named Minassian as a defendant. The parties stipulated to the filing of plaintiff’s fourth amended complaint which omitted Minassian. Though the trial court didn’t sign the stipulated order granting leave to file the fourth amended complaint, the court and the parties treated the fourth amended complaint as the operative complaint at trial. Hence, Minassian was not a party to the trial and it was error for the trial court to allow him to be added by a post-trial fifth amended complaint and to enter judgment against him absent evidence that Minassian was the named defendant’s alter ego or controlled its defense at trial.