check if Facebook like button liked on my webpage

On this webpage [login to view URL] i have a like button. when a user clicks like a comment box appears. when i unlike the button the comment box disappears this is ok but when a user has already liked the facebook page and comes to my webpage the comment box does not show. so im looking for a piece of javascript to check if a user has like the button on my page and if so to show the comment box. please check my source code of the website [login to view URL] to see what i have so far. let me know if you can do this? Thanks