How many times have you been entranced by a piece of soft music at a concert only to hear a mobile phone ring loudly and someone shout "wei!" 

Happily, a device has been developed to shut off mobile phones inside theaters. It cuts off the phone signal with a strong interfering radio signal.

The palm-size magic box is now widely used by famous theaters in Beijing.

Many theater managers say they are forced to use the device, since most people don't heed the request that they turn their phones off during performances.

Mobile phone pollution is not only a problem in theaters, but also in libraries, and even exam rooms.

(CRI July 7, 2004)