Web wrappers, however, are notorious for their fragility, because the format of web pages usually changes without notice. Previously, we developed a Java program, called Agent Toolbox, to cope with this issue (2). Agent Toolbox allows a user to produce an agent in a programming-by-example manner. More precisely, to produce an agent, the user simply browses the target website using the browser embedded in the user interface of Agent Toolbox to provide an example of a user session, and Agent Toolbox will generalize the example into a script that describes the user session.
