Enterprise systems are mission critical. As a result, ensuring their correctness is of primary concern. This paper aids to the analysis of Web Applications, focusing on the aspects related to the interaction of business logic and Web browsers. The method adopted is based on the Model Driven Architecture. First, the Platform Independent Model pplications is refined to create a new model called Abstract Description of Interaction (ADI). An ADI is a UML class diagram annoth OCL statements to represent an abstraction of the interaction between the thin client and the business logic. Secondly, the ADI model is automatically transferred to an Alloy model and analysed using the Alloy Analyser.