916.40  Petition for release.--Sections 916.31-916.49 do not prohibit a person from filing a petition for discharge at any time. However, if the person has previously filed such a petition without the approval of the Secretary of Children and Family Services or the secretary's designee and the court determined that the petition was without merit, a subsequent petition shall be denied unless the petition contains facts upon which a court could find that the person's condition has so changed that a probable cause hearing is warranted.