To run a macro when the Activate or Deactivate event occurs, set the OnActivate or OnDeactivate property to the name of the macro.
Remarks
You can use the ShowToolbar action in an Activate or Deactivate macro to display or hide a custom toolbar. Use the Activate or Deactivate event to display or hide custom toolbars when you have more than one form loaded at a time. If you have only one form loaded at a time, you can use the Open and Close events.
If you use a Deactivate macro to hide a custom toolbar on a form, also make sure to hide the toolbar in response to the Unload event for the form, because the Deactivate event doesn't occur when a form is unloaded. Don't use the GotFocus or LostFocus event to display or hide a custom toolbar on a form, because these events aren't triggered on forms that contain enabled controls.
You can't use the CancelEvent action in an Activate or Deactivate macro.