In this video tutorial, Chris Pels will show how to extend a standard ASP.NET server control and customize it for a specific purpose. Specialized controls provide an convenient way to implement standardized user interface elements for multiple web sites for individuals or teams of developers. In this example, see how to extend the DropDownList control to create a special purpose year selection control. Learn how to add properties for custom attributes that control the behavior of the range of years that can be displayed. Next, see how those custom attributes can be set in declarative syntax like standard attributes of a control. See how several additional properties can then be added to provide additional functionality for controlling the list behavior. Finally, see how an extended ASP.NET server control can be moved to a separate assembly so that it can be used across multiple web sites.