title: Control ChoiceBox JavaFX
body: <p>I'm writing my function is the dropdown address for my app by JavaFX. But its the function not being like I thought.</p>
  
  <p>I want to when I click choice box City and choice my city, choice box town will show towns belong to that city. But now when I change the city, the town does not change to match it. What can I use to fix it?</p>