An elevator target floor registration unit, which displays an estimated amount of time until an assigned elevator car arrives, reduces feelings of uneasiness. The applying of the programming pulse includes applying a quantity of energy to the phase change material to drive at least a portion of this material above a melting energy level. If the message indicates a change in the number of clients participating in the conference call, the media gateway simultaneously transfers the conference call and plays a prompt to the clients indicating the change. Transition metal complexes attached to polymeric backbones are also described.