FB user: is a fan? [duplicate]

This question already has answers here: Closed 11 years ago.

Possible Duplicate:

How to check IF user has ALREADY liked the face开发者_运维问答book page?

If a facebook user is a fan of our page, rather than displaying the "like" button on our website, we want it to show a "thanks" message.

On here: https://developers.facebook.com/docs/reference/fbml/visible-to-connection/ it seems "visible to connection" is the proper way to do this, however, this is only for fb apps? How can I do this to:

Include a like on the page

IF user is already fan, display other text instead?

Thanks

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I founded something: http://www.masteringapi.com/tutorials/facebook-api-check-if-a-user-is-fan-of-a-facebook-page/20/

I think you need to be logged in to Facebook and you need to know a token as well. Google "facebook graph api" and click first result.