In today's world web applications have become increasingly popular which mandates high reliability and high quality of web applications. With the growing complexity of web applications, developing a reliable web application in turn requires rigorous testing techniques which are exhaustive, efficient and cost effective. Several researchers have proposed varied methodologies, frameworks and tools to generate test cases for testing web applications by extracting the navigation behavior of web applications using forward or reverse engineering tools. In this paper we propose a Model Based Test Case Generation technique wherein the model representing the navigation behavior of a web application is derived from requirements and low level design. The model is traversed to generate test sequences which can later be incorporated with input data to generate test cases. The proposed approach is also demonstrated by means of a case study.