Most of the commercial and industrial web applications are complex, difficult to implement, risky to maintain and customization requires deep understanding of the requirements. As today's software market more competitive, productivity becomes a major concern in software development industry. Research showed that customization and reusability can greatly increase productivity; improve software quality, save millions of dollars and countless hours in development time. Unfortunately, implementing systematic reuse and customize existing system has proven to be a difficult process. As web engineers continue to struggle with cost and time, reuse has emerged as a sound engineering principle and practice in many fields. However, technology for completely integrated user interface, reuse design, customization and implementation is still immature. This paper contributes in the field of reusability and customization.