window.fbAsyncInit = function() {
        FB.init({
          appId  : '477400305610609',
          status : true, // check login status
          cookie : true, // enable cookies to allow the server to access the session
          xfbml  : true  // parse XFBML
        });

        FB.login(function(response) {
        if (response.authResponse) {
            console.log('Welcome!  Fetching your information.... ');
            var attachment = {
                'name' : '¡Yo resolví la trivia y estoy participando por un Samsung Galaxy SIII!',
                'caption': 'http://www.facebook.com/movistarperu/app_477400305610609',
                'link': 'http://www.facebook.com/movistarperu/app_477400305610609',
                'picture': 'http://samsunggalaxysiii.serviciosmovistar.com/images/ico-compartir.jpg'
                };

            FB.api('/me/feed', 'post', { message: attachment }, function(response) {
              // lo que quelas
            });
        );
        } else {
            console.log('User cancelled login or did not fully authorize.');
        }
        }, {scope: 'publish_stream'});

   };

  (function(d){
     var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
     if (d.getElementById(id)) {return;}
     js = d.createElement('script'); js.id = id; js.async = true;
     js.src = "//connect.facebook.net/en_US/all.js";
     ref.parentNode.insertBefore(js, ref);
   }(document));