title: Django - Admin - on form change
body: <p>I have a general question to the django-admin.</p>
  
  <p>Is it possible to react on form changes?</p>
  
  <p>I have a select field in my django-admin detail site. Whenever i change the data from the select field, i want to change fields which are readonly.</p>
  
  <p>Anybody ever dealed with this issue?</p>
  
  <p>Thanks and Greetings</p>