ms-access the ability to enter multiple values into a textbox on a form

i have a textbox on a form and i would like the user to be able to choose from different values but also be able to enter their own values, how do i do this?

i would like to clarify that the user should be able t开发者_JAVA百科o enter multiple values into the same textbox

I suggest that you don't. A subform to a table of values related to the main table would seem to be the way to go. You can make data entry for the field a combo that is not limited to list. Often a link back to the sub-table will suit in such a case.