The autocomplete control adds the common autocomplete paradigm to text boxes. The control is loaded with features to help you customize the behavior, look, and feel in different ways. History: Include end user edited values in a history collection that is persisted in the client machine for future sessions. Auto-append: Besides auto suggest, the control can also auto-append the top item in the list to the text box. Custom Filtering: Dynamically filter the items that will make it to the drop-down as the end user types in text. Selection Mode: Single or multiple items can be selected. Optionally display a combo box-type drop-down button to display all the options.