A method for warning of a residual amount of liquid detergent includes: calculating a total use amount of liquid detergent by adding up a use amount of liquid detergent whenever a washing process is performed; and comparing the total use amount of liquid detergent to a reference amount, and warning of a residual amount of liquid detergent according to the comparison result. The polymer electrolyte membrane can save manufacturing cost of a fuel cell and improve proton conductivity and mechanical strength. This makes it possible, for example when used in a monitor vehicle, to monitor the area behind and next to the motor vehicle with a single transmitting antenna. However, before the call is connected, the user enter a telephone number where the system will call back to bridge the call, and abuse criteria relative to the web-based user’s telephone number are evaluated. At least a contact part of the belt body with a pulley is formed of a rubber composition which contains ethylene-\u03b1-olefin elastomer as a rubber component but contains substantially no short fibers and which has a rubber hardness of not less than 80 but less than 95 when measured with a type A durometer in conformity with JIS K6253. The combined confidence values represent a probability that the received statement is evaluated as true.