title: Form fields in hidden DIV
body: <p>I have a form with some fields that are in a hidden DIV (style="display: none;"). The user can click a button that displays these additional fields if they wish.</p>
  
  <p>Now if the user submits the form in its "compact" state, the form variables in the hidden div are also submitted and displayed in the address bar.</p>
  
  <p>How can I change this behaviour so that only the visible form fields are submitted?</p>