Combobox component in C#

I need a combobox that will only display possible results, given the user input in the edit box. The coding must a C# component suitable for incorporating into a larger project. For development use the file of country names provided. The maximum number of items shown in the dropbox should be 5. If the user tpyes the letter "A" the dropbox will show: Afghanistan Albania Algeria American samoa Andorra If the user then types "AR" the dropbox will show only the possible counties (up to 5) in this case: Argentina Armenia Aruba Then finally if the user types "G" only Argentina will be in the dropbox. It is important that the dropbox is no larger than that needed to hold the items. So here its size would be 5 items, then 3 then 1. If the user should backspace it in edit box it would go back to 3 items.