A viewer in the form of a browser displays a Web page which is accessible by an associated unique identifying information. The associated identifying information is a URL. The viewer includes a definition management note which stores a number of times of display of any Web page which has been accessed by an associated URL. The viewer also includes an importance degree control unit to count a number of times of display of any Web page accessed by the unique URL. The importance degree control unit outputs a number for storage by the definition management note. When the counted number of times of access of a unique URL exceeds a threshold value, the associated Web page is automatically updated to a bookmark by way of the unique URL. A number of different processes may be executed to sort the URLs registered in the bookmark according to a degree of importance. The different processes include assigning different colors to the URLs or changing a display in a Web page accessed by a registered URL.