The number of end-users using the Internet increases on the inside and outside of offices. Enduser-initiative development of applications has become important for automation of their own tasks. This paper describes a multi-agent framework for the MOON(multiagent-oriented office network) systems which are distributed systems including window work in electronic commerce. Especially, since the window work is considered as a metaphor of the interface between service providers and the service requesters for web services, this paper is focused on automatic filling in a form by a user agent in collaboration with a broker agent, which is one of key technologies for electronic forms defined as HTML documents. At the first step, a satisfactory success rate is achieved by using cognitive rules based on a form layout. That is, the case rule of { IF #case THEN #action } is introduced. The #case is composed of the four attributes and their values based on cognitive information on the upper, left, right and lower sides of the input field. The ontology of concept names is introduced for different expressions of the same meaning. Furthermore, by the reasoning of similarity on incomplete matching of the case parts of rules, the success rate of automatic filling is greatly improved. At the second step, the success rate is improved further to 100% by using experiential rules of other users, which the broker agent gathers up.