I can't select a value in the list box, drop-down list box, or combo box.

You may have misspelled the field name in the ControlSource property box. You use the RowSource (forms and reports) or the ListRowSource (data access pages) property to specify the items that make up the list. When you click an item in the list, Microsoft Access needs to know where to store the value that you selected. You use the ControlSource property to specify where the values are stored.