how to check check if Facebook like button liked on my webpage

On this webpage
http://www.corkdiscos.com/testimonials.html

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 http://www.corkdiscos.com/testimonials.html to see what i have so far.

any help would be greatly appreciated