This example shows how you could add a sub-menu dynamically.
The sub-menu name is "AAA KUAL Music".
The sub-menu has two states: hidden and visible.
When "AAA KUAL Music" is hidden, KUAL displays button "AAA add KUAL Music" which adds the sub-menu.
When "AAA KUAL Music" visible, KUAL displays button "AAA remove KUAL Music".
