Hey there. I just went through the site, but couldn't find anywhere that you're actually trying to show the button. Can you post a link to the page with either the JFBCLogin module enabled, or that you're using the {JFBCLogin} tag to show the button?
I do see the Javascript error, and I think that could be part of the problem, but will need to see the page to really diagnose the problem. The error that you're getting is from your template, and I honestly wouldn't know how to fix that.. you'd need to contact the template provider.
Hope this helps, and let us know where we can look to help further!
Not able to get the plugin to work
