A Web page is displayed on a display screen of a digital camera. The Web page is composed of an image corresponding to one frame. When a radio button corresponding area is clicked, a http request indicating that the radio button corresponding area is clicked is transmitted from the digital camera to a conversion server. In the conversion server, a Web page in which the clicked radio button corresponding area is marked with a solid circle is generated. A html response representing the generated Web page is transmitted from the conversion server to the digital camera. The Web page in which the clicked radio button corresponding area is marked with a solid circle is displayed on the display screen of the digital camera. The radio button function of the Web page can be substantially utilized.