By default, the AutoSearch property is exStartWith. The AutoSearch property has effect ony if the control's Style property is DropDownList, and AutoSearch property of the control is True. Use the AutoSearch property to define a 'contains' incremental search. If the AutoSearch property is exContains, the control searches for items that contains the typed characters. The searching column is defined by the SearchColumnIndex property. Use the ExpandOnSearch property to expand items while user types characters in the control.