735 ILCS 5/6-118: Plaintiff's proof.

It is not necessary for the plaintiff to prove that the defendant was in possession of the premises, or claims title or interest therein at the time of bringing the action, or that the plaintiff demanded the possession of the premises, unless the defendant in his or her answer verified by affidavit specifically denies that he or she was in such possession, or claims title or interest therein, or that demand of possession was made.