Combobox in c#

Question

hello sir,

    I have one question.I am using Visual Studio 2010 With c# windows application.In my application i have one combobox feild. write now my combobox is empty.but i want when i am run my application i can add the value into the combobox. Means user can add it's own "New Item" in the combobox. and whatever i have add it will still show when i will run application next time.