By default, the AutoSearch property is True. The auto-search feature is is commonly known as incremental search. An incremental search begins searching as soon as you type the first character of the search string. As you type in the search string, the control selects the item  ( and highlight the portion of the string that match where the string (as you have typed it so far) would be found. The control supports 'starts with' or 'contains' incremental search as described in the AutoSearch property of the Column object. Use the ASCIILower and ASCIIUpper properties to specify the set of lower and upper characters when auto search feature is enabled. Use the ExpandOnSearch property to expand items automatically while user types characters to search for a specific item. Use the MarkSearchColumn property to specify whether the control draws a rectangle around the searching column. The SearchColumnIndex property determines the index of the searching column.