Automated tests are important for Web applications as they grow more complex day by day. Web application testing frameworks have emerged to help satisfy this need. However, used without a model that is designed for system evolution and realization, maintaining test code becomes cumbersome and inefficient. This paper describes an activity oriented approach to engineer automated tests for web applications with reference to a web application developed for grant funding agencies. In this approach, the developer defines a domain model to represent application state, and uses a test activity graph comprised of self-validating user interactions to verify application correctness. We have implemented a test code generator called iTester using activity-oriented approach.