.variables facebook credentials.txt

<script>
  window.fbAsyncInit = function() {
    FB.init({
      appId      : '$facebook.appid',
      xfbml      : $facebook.xfbml,
      version    : '$facebook.ver'
    });
  };

  callout(document, 'facebook-jssdk', 
          '//connect.facebook.net/en_US/sdk.js');
</script>