In facebook connect, how can I check if a user is a fan of my facebook page? Is it possible to track?

Question

I am trying to determine if a user is a facebook fan. I load the facebook JS library and initialize:

Answer 1

Please note that @daaku's answer is true only in two cases:

1. If your app grant the user_likes permission or
2. The user's pages privacy setting is set to everyone.

Source:

Note: This call no longer requires a session key. You must pass a user ID if you don't pass a session key. If the user's pages are set to less than everyone privacy, you must ask the user for the user_likes extended permission and include a valid user access token in the API call.

Try this code to better understand:

Check if user Likes the Page (wrong way)
Check if user Likes the Page (right way)

Working example.

I've also written a full tutorial about this today.