9. a. A tribunal of this State shall serve as an initiating tribunal to request a tribunal of another state to enforce or modify a support order issued in that state.b.A tribunal of this State having continuing, exclusive jurisdiction over a support order may act as a responding tribunal to enforce or modify the order. If a party subject to the continuing, exclusive jurisdiction of the tribunal no longer resides in the issuing state, in subsequent proceedings the tribunal may apply section 28 of this act to receive evidence from another state and section 30 of this act to obtain discovery through a tribunal of another state.c.A tribunal of this State which lacks continuing, exclusive jurisdiction over a spousal support order may not serve as a responding tribunal to modify a spousal support order of another state.