Rich Internet Application (RIA) is becoming popular based mainly on high-speed network and diversified connection methods. Unlike traditional web applications, RIAs are working mainly on client side and invoking remote services located on server side as needed. Unlike traditional web applications, RIA are mainly working on client side and invoke services located on server side. That is, main functionalities such as validation, screen transition and business logic are processed at client side. This paper describes the design and implementation of modularity oriented framework that helps RIA developers to divide processes at client side into functional units and develop each function independently. This framework divides the functionalities working on client into three units, including validation of input values, screen dependent processes and shared processes and makes it possible to work these functionalities as a single application by using event model and naming convention instead of programming codes for binding them. This framework provides coherent RIA development style with a number of RIA developers.