This section applies if there is a conflict between a custody order of a court of this State and a custody order of a court of another state. Except as provided in subsection (c) of this section, a custody order of a court of this State prevails over a custody order of a court of another state. A custody order of a court of another state prevails over a custody order of a court of this State if the court in the other state passed its custody order: after the custody order was passed by a court of this State; and in proceedings in which the lawful custodian under the custody order of a court of this State: consented to the custody order passed by the court of the other state; or participated personally as a party.