making a combo box editable

i want make the combo box editable in c# that is it shouldaccept from key board and from drop doen but it is replacing the thins i want to appent the text typed and selected any help .

From stackoverflow

• You need to:

  1) Set the AutoCompleteMode property to AutoCompleteMode.SuggestAppend

  2) Set the AutoCompleteSource property to AutoCompleteSource.CustomSource

  3) Set the AutoCompleteCustomSource property to an AutoCompleteStringCollection of your possible matches.

  Nicholas H : Please accept my answer if you're happy with it.