title: Facebook Reachability Check from javascript
body: <p>I am integrating Login with Facebook using JS SDK, I use Following code to Load FB SDK</p>
  
  <pre><code>$.getScript('//connect.facebook.net/en_UK/all.js', function() {
              FB.init({
                  appId: MY_APP_ID,
                  channel: true,
                  channelURL: 'https://www.fbrell.com/channel/',
                  status: true,
                  cookie: true, // enable cookies to allow the server to access the session
                  xfbml: true // parse XFBML
              });
  });
  </code></pre>
  
  <p>Now All I want to check whether Facebook is accessible from user's machine before Initializing SDK, Any Solution for that ?</p>