You want users to be able to add a single value to a list item.
How do you achieve this?
A.
Set the List Style property to combo box.
From the When-List-Activated trigger, call the Add_List_Element built-in.
B.
Set the List Style property to Tlist.
Form the When-List-Activated trigger, call the Populate_List built-in.
C.
Set the List Style property to poplist.
From the When-List-Activated trigger, call the Add_List_Element built-in.
D.
Set the List Style property to combo box.
From the When-List_Changed trigger, call the Add_List_Element built-in
E.
Set the List Style property to Tlist.
From the When-Validate-Item trigger, call the Populate_List built-in.
F.
Set the List Style property to poplist.
From the When-Validate-Item trigger, call the Add_List_Element built-in.