RELATED INFORMATION SEARCH METHOD, RELATED INFORMATION SEARCH SYSTEM, AND COMPUTER-READABLE MEDIUM HAVING STORED THEREIN A PROGRAM

A system according to the present invention searches for information related to entered text and presents searched information to a user with a minimum interruption to user's document formulating work. An input analyzing module 11 analyzes text entered by the user and extracts a search key. A related information searching module 12 searches a related information storage device 3 for information on the search key. A storage module 16 stores therein the search results collected for a plurality of past search keys including the latest search key and the positional information on each search key within a document. A controlling module 13 searches the storage module 16 for the search key corresponding to the position of a cursor. The controlling module issues an instruction to change a search button to a first display format if there is no related information, or an instruction to change the search button to a second display format if there is related information. In response to the instruction, a search instruction accepting module 14 changes the format of the search button on a display device 22. When the user backspaces the cursor to a previously-extracted search key, the system searches the storage module 16 again for information on the previously-extracted search key and changes the format of the search button according to the search result.