I have a Fan Page and I need to post something on users Wall after clicking Like Button. Moreover I need to display different content for users who "Like" the page and for users who don't "Like" the page. Is there an application like "Static iFrame Tab" which already solves this? If not, then how to post something on users Wall? I downloaded the facebook.php file, but I haven't managed to find the required function there.Answer1:
The user's 'like' status can relatively easily be returned by decoding the signed request sent by Facebook to the page.
I've built a simple fan/like gate that is available over on <a href="https://github.com/MozMorris/Facebook-Fan-Gate" rel="nofollow">GitHub</a> - it might help you get up and running.