So as to compare an amplitude of a differential input signal to a threshold, a signal detection circuit includes first and second matched input signal level-shifters, a comparator threshold generation circuit, and a two-stage comparator. The magnetic field detection portion is capable of detecting a magnetic field parallel to a surface of the substrate in a case where a current flows through the magnetic field detection portion in a vertical direction of the substrate. The guide bolt is pivoted to the valve bolt. Permission to access or modify contact lists for chat session participants can be defined prior to establishment of the communication session andor changed during the communication session.