EMB500 Captain experiences in flight CAS warning for brake failure. Upon landing brakes are found to function normally.

Narrative

Crew experienced a brake failure in flight; annunciated in the aircraft CAS system. Crew declared an emergency and asked for the longest runway which was around 10;000 FT long. Upon landing the regular brakes were tested prior to applying emergency brakes and regular brakes worked so the aircraft was stopped using regular brakes and the emergency brakes were guarded upon taxiing into the parking area. Nothing else was noted.