An information terminal support server which manages user attribute information corresponding to user specification information and supports collaboration between first and second information terminals loaded with browsers and connected to a content server, the information terminal support server, content server, first information terminal and second information terminal being connected via a network, said information terminal support server comprising:
- (a) a message checker for determining whether or not user specification information extracted from a message sent from a content server in response to a request from the first information terminal meets a predetermined condition;
- and
- (b) an HTTP editor for inserting a program for outputting predetermined data into the message when the predetermined condition is met.