How add instatnt search items to combobox dropdown items in c#.net

Question

Hi,
i have combobox in windows form application i need to add insatat search items to combobox dropdown items smilar like google search
when ever i type a text in the combobox the matched text of the list box is to be added to the combobox dropdown items and this searched results are keep on changing for every new charecter pls any suggestion ...........