The application of Ajax asynchronous refresh in general used database maintenance system

Classic web application model uses synchronous refresh mechanism. It has poor interaction with users. And for the http protocol is stateless, it can´t update part of the page with out refreshing it. Sometimes user wants to keep the current state of a page when they can communicate with the server with sub steps. Ajax is a way to update part of the page without refresh it, so we can solve the question above by using Ajax. The essay achieves the universal database of navigation combined with Ajax technology. We used the asynchronous refresh technology of Ajax. It makes pages faster updates, and more interactive with the user.