In this paper we discuss how Web site maintenance can be improved by making page structure and contents independent. This is the principle used in TANGOW (Task-based Adaptive learNer Guidance On the Web) for designing and maintaining Web-sites. In TANGOW, the information structure and contents are managed independently, what facilitates the maintenance tasks. It also allows the specification of a common design pattern for all the final HTML pages, which the system dynamically generates starting from static HTML pieces. In the first section we introduce some common issues and problems in Web-site development. The TANGOW system is presented in the second section, focusing on those characteristics that make it useful for the development of Web-sites. Based on a real world example, the next section shows how TANGOW helps to solve the problems mentioned in section 1. Finally, some conclusions are taken from the described application