title: How to ask for optional Facebook permissions
body: <p>We use Facebook Connect on our web site. We have some mandatory and some optional permissions. Is it possible to get FB to display a check box next to the optional ones? I've seen some sites that do this but maybe they are displaying their own dialog.</p>
  
  <p>Once an optional permission has been granted, what is the best way to allow the user to revoke just it?</p>
  
  <p>We are using the Javascript SDK but could also implement something in PHP if needed.</p>
  
  <p>Thanks!</p>