Create Rich Web Apps with AJAX: Figure 2
Complete Fields Automatically. The AutoCompleteExtender can be used to save end-user key strokes by providing suggestions as they type into a textbox. This extender control is part of the ASP.NET AJAX Toolkit and retrieves data by calling an ASP.NET Web service. The Web service takes the user input, finds matching data items, and returns them to the control in the form of a string array.