Limit the choices of a combobox to its collection

I must be missing something real obvious here but I can not figure out how to limit a combobox to the items in the drop down only.

For instance if I have 3 choices in my drop down list:

Red
White
Blue

I don't want the user to be able to type yellow into it. What am I missing?

Under the DropDownStyle property are three options. The last one DropDownList limits the combobox to only what is in the list. Im 99% on that, if not its one of the other two options.

You nailed it. Thank You.