In this article we have discussed two typical ways (ExtenderControl and WebControl) to enhance ASP.NET AJAX framework's client-side functionality from the point view of the server side. First, we should be aware that to construct Ajax-enabled server controls we must be quite familiar with the concepts of script descriptors and script references, which are the main objects used by server controls to instantiate client components and load script files in a web page. Second, the two related samples provided in this article are still pretty elementary with still much to be improved. Third, in contrast with the methods introduced in the earlier article "Explorer Ways to extend ASP.NET AJAX Client-side Function," the ways introduced in this article are not easy to grasp either. In fact, to follow the server-side way to construct an AJAX-enabled control we have to gain a good understanding with the ASP.NET server control development as well as the JavaScript techniques. However, apparently the server-side solution greatly lessens the burden the ASP.NET developers bear.

In real scenarios, to develop ASP.NET AJAX based components (or controls) we should first do careful research into the practical requirements as well as the developers' familiarities with necessary developing tools. Then the next thing for us to do is to decide which solution to follow to develop which kind of component.