Populate a 2nd list box after selecting a record in the 1st listbox

How can I populate a 2nd listbox on a form (multi select = Simple), with records  after selecting a record in the 1st listbox.  The 1st listbox shows categories.  When I select one of them I want the related sub-categories to display in the 2nd listbox.  How can I do this?
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

This is called cascading combos and there are lots of variations on how to do it.  My preference is for the dependent combo to use a query as the rowSource with a WHERE clause that references the parent combo:

Where MyField = Forms!yourForm!ParentCombo

Then in the AfterUpdate event of ParentCombo,, you requery the dependent combo


So, it's one line of code plus a where clause in your RowSource query.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Access

From novice to tech pro — start learning today.