title: how to get user email in facebook graph api
body: <p>I am use facebook graph api for Login with Facebook account.
  My graph api version is 2.12.
  The problem is i can't get user email, my code is like this</p>
  
  <pre><code>$dialog_url = 'http://www.facebook.com/dialog/oauth?client_id=' . FACEBOOK_APP_ID . '&amp;redirect_uri=' . $callback_url;
  </code></pre>
  
  <p>//token access</p>
  
  <pre><code>$url = 'https://graph.facebook.com/v2.12/me?fields=id,name,email&amp;access_token='.$access_token;
  </code></pre>
  
  <p>But i only get id and name not email, i don't know why, somebody helps me.</p>