an agent interface controls display of an agent and receives a request from a user . a search engine searches for an action script describing a procedure of controlling the agent interface in accordance with the request input from the agent interface . an action script executing engine executes the action script searched by the search engine . thus , since action scripts adapted to be used for the same kind but different types of electrical household appliances are prepared in action script db , for example , the different types of electrical household appliances can be operated by the same procedure and interfaces can be unified .