Determines or specifies which value or option in the combo box is selected. Read/write Variant. The Value property returns or sets a control's default property, which is the property that is assumed ...

Returns or sets a Variant that specifies the value in the BoundColumn of the currently selected rows. Read/write.

In VBA for access 2000, it was really easy to prevent someone from entering a value that was not in the list. In the combobox's properties, you just change the "LIMIT TO LIST" property to ...