Set the Multi Select property of your List Box (not combo box, as in your
subject line, as these cannot be made multi-select) to either Simple or
Extended.
Cheryl's rather brief reply isn't going to get you very
far,as you can select multi values but not do anything
with them without some rather involved code. See Microsoft
Knowledge Base article 135546 for the code and be sure to
have have DAO3.6 references enabled in the VBA Tools menu.