Navigation system

A car navigation system which receives information from an information service device by using a communication line, comprising a communication part which communicates through said communication line, a display part, a plurality of screen switch buttons, and a processing part which accepts setting from an operator and performs the processing,

• wherein said processing part has;
• a screen change processing means for allowing the operation screen displayed in said display part to change according to the content of the operation on said plural screen switch buttons by the operator, the operation screen under the display, and the layered structure of said plural operation screens, the operation screens to receive the setting from the operator being provided hierarchically,
• a communication method judgment means judges whether the communication method in said communication part is a circuit switching method or a packet method,
• a communication control processing means which establishes communication line between said information service device and this system by controlling said communication part when it is necessary to receive the information from said information service device in order to process according to the setting given by the operator through each of a series of operation screens displayed in said display part, and cuts off said communication line when it is detected that said communication method is the circuit switching method after said information is received, the communication control processing means, or maintains the connection of said communication line when detected that it is the packet method.