FB.getLoginStatus(function(response) {
  if (response.status === 'connected') {
  document.write("Looks like you're logged into Facebook and our app :)");
    // the user is logged in and connected to your
    // app, and response.authResponse supplies
    // the user’s ID, a valid access token, a signed
    // request, and the time the access token 
    // and signed request each expire
    var uid = response.authResponse.userID;
    var accessToken = response.authResponse.accessToken;
  } else if (response.status === 'not_authorized') {
<div class="overlay"><div class="overlay-content"></div></div>
    // the user is logged in to Facebook, 
    //but not connected to the app
  } else {
<div class="overlay"><div class="overlay-content"></div></div> 
    // the user isn't even logged in to Facebook.
  }
});
</script>