Guidance system using changeable signs

A guidance system for guiding a user to a selected target among a plurality of targets located within a defined area, comprising:

• a portable unit to be carried by the user, including a memory for storing target information identifying the selected target, and a transmitter for transmitting a target signal representative of the target information;
• a target device adjacent to said selected target, including a receiver for receiving signals transmitting by said portable unit, and a target indicator or indicating that a received signal is said target signal representative of said target information identifying said selected target;
• a computer for storing said target information;
• and a check-in unit linked to said computer for communicating with said portable unit to download into its memory said target information identifying said selected target;
• and a check-in unit linked to said computer for communicating with said portable units to download into its memory said target information identifying said selected target.