Develop a JS function to read out like button status via CSS

Hello, I need a javascript function which checks the status of the facebook like box or button (Box: [login to view URL] / Button: [login to view URL]) within my webpage and recognizes if the current user is a fan or is not a fan or is not logged in to facebook. Possible Solution: 1. Read out CSS class of "like" in like box/button. 2. Define fan status of current CSS class (fan / no Fan / not logged in to facebook). 3. Return status as a function result For further questions, just write a comment. Best, Olli