This page shows how to use client-side API to implement dependent (AKA cascading) lookup controls.

In this example, when a user selects a country from the dropdown list, the City dropdown list is automatically populated with the appropriate list of cities. Open Insert or Edit forms to see these features in action. Click the button to get familiar with the event handlers' code.

Note. In this example both Country and City fields are stored in the table. The best practice is to store only the city (which explicitly determines the corresponding country) and use Cascading Combobox or Dynamic Cascading Combobox as this will free the database of modification anomalies. Learn more about normalization.