building site as well as positional information of a delivery site i e the current location for that the current location inquiry function inquires of the gps equipped portable telephone 4 carried by the customer about the current location when the latitude and longitude of the current location is returned as location information from the gps equipped portable telephone 4 the map database 11 is searched based on the location information the latitude and longitude are converted into map data in a corresponding administrative division and the map data is saved in an object file 14 then when the customer wishes to order products an ordering function is used to perform quotation processing when a definite order is placed it is saved in an order data file 15 if an inquiry about the arrival time of a delivery truck is made by a construction contractor who is receiving the delivered goods or by a sales person the delivery time calculation section 10 calculates estimated arrival time based on the current location of the delivery truck and location of the delivery site and replies to the inquirer for that the current location inquiry function inquires of the gps equipped portable telephone 4 carried by the delivery person driving the delivery truck about the current location when location information about the current location of the delivery truck is returned from the gps equipped portable telephone 4 it is converted into map data in the map database 11 then the location of the delivery site is determined based on a shipment data file 17 basic data about traffic conditions and necessary time are extracted from delivery route data 16 the estimated arrival time at the.