405 ILCS 5/3-900

(a) Any person committed on an inpatient or outpatient basis on court order under this Chapter or under any prior statute or any person on his behalf may file a petition for discharge at any time in the court of the county where the recipient resides or is found.

(b) The petition shall set forth: (1) the name of the recipient; (2) the underlying circumstances and date of the order; (3) a request for discharge from the order; and (4) the reasons for such request.