Information storing medium, personal digital assistant, and electronic commerce system, electronic commerce method

摘要

An electronic commerce system which uses personal digital assistants (11-1n) having detachably mounted thereon memory cards (IC chips) (M1-Mn) each carrying an identification code (ID). For instance, when a person carrying a personal digital assistant (PDA) (1n) tries to pass a gate, a reading device (40) reads an identification code carried by an IC chip (Mn), and, when a permission to pass the gate is obtained, opens the gate to let him pass. A server (30), on receiving an electronic commerce request from, e.g., a PDA (11) via a network (20), records an identification code carried by an IC chip (M1), displays the recording on the display unit of the PDA (11), and at the same time gives a passing permission to the reading device (40) when an identification code output from the reading device has already been recorded.