Facebook Page Tab Like Gate

fb-page-tab-like-gate.js

var appId = 'XXXXXXXXXXXXXXX';
// Taken from the App's configuration page

window.fbAsyncInit = function() {
  FB.init({
    appId: appId,
    status: true,
    cookie: true,
    xfbml: true
  });
    
  FB.Canvas.setAutoGrow();
};
  
FB.getLoginStatus(function(response) {
  if (response.status == "connected") {
    FB.api("/me", function(user) {
      if (user != null) {
        FBID = user.id;
        PageID = "XXXXXXXXXXXXXXX";
        // Taken from http://graph.facebook.com/PAGE-NAME [app parent page]
        
        FB.api("/me/likes/" + PageID, function(response) {
          if( response.data[0] ) {
            IsFan = true;
            // Action code here
          } else {
            IsFan = false;
            return false;
          }
        });
      }
    });
  }
});