DANCIN' ON AIR -- produced from 1981-1987 by Michael Nise and his father, Frank -- was the forerunner of DANCE PARTY USA. Initially, DANCIN' ON AIR was broadcast LIVE to 7 states.  The show's creators / producers worked out of their Camden, NJ offices. The show's TV studio was located in Philadelphia.   Frank Nise was 70 years young when DANCIN' ON AIR first broadcast. That makes Frank the "oldest living teenager" at the time, and an excellent candidate to claim the honor of being, "the oldest executive producer of a young adult music TV program."   Over 20 years later, Philly's "kids" are still Dancin' On Air.  The daily TV teen dance will celebrate its 23rd anniversary on October 12, 2004.   The program that brought teens from 7 states rushing home after school to hear the latest music, learn the coolest dances, see the hottest stars and watch their heartthrobs (the show's "regulars") is still getting fan mail. "It was more than a dance show, it was a teen lifestyle program