[AccessD] Help with combo box

It may be VBA only and all it does is drop the list automatically. 

Susan H. 

Susan

The only property list I can see is the property dialog box for the whole
control. What I need to setup is a way that makes it impossible for the user
to change their selection once they have made one (unless they delete the
record first) but still lets them use the double-click event to open the
form to change the rental type for the title.