Regal Theaters, the nation's largest theater chain, has begun testing devices in 25 of its locations that allow patrons to summon ushers if audience members use cell phones or become unruly. Regal Chief Executive Michael Campbell told the Reuters Media Summit in New York Wednesday that a second button will notify management of faulty projection, a third about uncomfortable room temperature, and a fourth about any other problem. Campbell said that ordinarily customers won't say anything such problems while the film is running. "They just will complain on their way out or, in the worst case scenario, they don't come back." He said that he expects the device to be available nationwide next year and that it will be given to "mature" audience members, who will receive free popcorn for their efforts.