title: FB.ui not returing post id in response
body: <p>I am following this thread <a href="https://stackoverflow.com/questions/19130267/is-it-possible-to-add-a-link-to-download-a-file-that-can-only-be-downloaded-by-s/19131177#19131177">Is it possible to add a link to download a file that can only be downloaded by sharing it on Facebook?</a> to detect if user share my given link or not, If user share then allow him to access the next level. </p>
  
  <p>This is how i am doing: </p>
  
  <pre><code>FB.ui({
                  display: 'popup',
                  method:  'share',
                  href: 'url-here',
              } , function(response){
                  console.log(response.e2e)
                  if (response &amp;&amp; response) {
                      $.ajax({
                          url: ajaxurl, 
                          type: 'post', 
                          data: {action: 'unlock_om_gmap'}, 
                          success: function(res) {
  
                          }
                      });
                  }
              });
  </code></pre>
  
  <p>But everytime its returning <code>Object { e2e="{"submit_0":1406412308276}"}</code> not any post id. Is there anyone familiar with this issue? How do i check if user shared my link or not?</p>