user first a party is selected at step s 12 1 the degree relationship index of relationship desired to be set with respect to the party is selected at step s 12 2 and the remaining required details are input at step s 12 3 in this case the party may be a person which registers a specific script to the bulletin board of a community or a club to which the user subscribes the simultaneous recipient user receiving a carbon copy of information content provided to user a or a user which is known at a communication step with another user the degree of relationship is differently set through gradation of relationships desired to be established with a corresponding user and therefore the range of information opening as other required items an incentive to be paid upon establishment of relationships is proposed to user a or a user can input its own personal information furthermore for example the upper limit of a route cost below xx point the limitation to the degree of kinship for example below 5 degree of kinship whether to provide a potential optimal route or limitation to the number thereof may be options at the time of searching for routes by a server fig2 is.