An armrest of a chaise longue includes a seat, a backrest and two armrests. At least one of a plurality of automated signature texts is associated with at least one encoding type of a plurality of encoding types, at least one message transport type, or with at least one predeterined recipient attribute or the outcome of a comparison of the recipient attribute with the sender’s attributes. When maximum value of the detected value of the sensor detected during a determination period is lower than a value stored in a storage unit and a stack state has not been detected by the stack detecting unit during the determination period, the count processing unit does not count up a counter and does not reset the counter. With the invention, only the first source or the second source is connected to the ground and the other is insulated from electrical connections.