A personal digital assistant (PDA) detects its position by a two-axis acceleration sensor provided therein. While the PDA is within a communicable range where the PDA can communicate with the printer, a position of the PDA, which is located at time when the position of the PDA is detected, is recorded as an origin point and the origin point is periodically updated to the detected position. When the PDA moves to a position (current position) through a position which is out of the communicable range of the printer, guidance information for guiding the PDA into the communicable range of the printer is created based on a relative positional relationship between the current position and the origin point, which is recorded immediately before the PDA moves to a position out of the communicable range, and then the guidance information is displayed on the PDA.