title: how to stop facebook sdk from returning uid in $facebook->getUser()
body: <p>so I'm trying to program the Facebook logout feature for my site</p>
  
  <p>The thing is using the facebook logout button will instead logout the user from the Facebook website not from my website</p>
  
  <p>so my current logic is when the logout button is clicked, it instead calls my app's logout feature and session gets cleared etc</p>
  
  <p>but then I also have logic somewhere else in which if $facebook->getUser() returns the uid properly, fetch the user info from the db and set him as logged in</p>
  
  <p>is there a way to prevent $facebook->getUser() from returning the proper user id? </p>
  
  <p>IE when user clicks on the logout, he shouldn't be logged out of the actual facebook website, but also $facebook->getUser() should also not return a proper id so that he won't be automatically relogged in again </p>