A back light module is provided. This is accomplished through the innovative use of video multiplexing, software, control electronics, and special viewing glasses. When there is a request for distribution of mail from an advertiser, in the case where a distribution rank is designated by a user who is a receiver of the mail, with respect to the mail of the advertiser, the mail server summarizes the contents of the mail in accordance with the designation of a summarization degree of the designated distribution rank, and send them to the user. The disks move or slide relative to the support to indicate one or more symbols to a player based on a triggering event in the game.