title: Detect Facebook language
body: <p>I'm working on a Facebook application where there will be 2 languages, obviously the user can switch himself, but I would also like to detect what language the user is using on Facebook so I can set that as a default one.</p>
  
  <p>I checked the opengraph API, but there doesn't seem to be any way to detect this, are there any other options?</p>