Portable telephone set, key operation validity/invalidity notification method for use with the portable telephone set and program for the method

摘要

A key input discrimination unit discriminates whether the input key is valid or not by referring a key allocation information. A control unit controls a speaker to generate different type of beep sounds based on the discrimination result so that the user is informed about the valid or invalid key operation based on the type of beep sound output by the speaker. Independent claims are also included for the following: (1) a key operation validity/invalidity notification method; (2) a program for notifying the validity/invalidity key operation to the user.