Last stall information is transmitted if the last stall standing function is enabled, one of the stall elements was active during the last clock cycle, no stall condition exists during the current cycle and the stall threshold has been met. Accordingly, the switching device which can be easily assembled is obtained, including an operational button which returns to a predetermined position in a hole with the release after pushed down. to decompose the ammonia from the fly ash. The reflectivity of a reflector can be changed by changing a state of a thin film, a liquid crystal layer, or a suspended magnetic particle layer. Once established, the communication data can be transmitted across community borders.