title: Facebook PHP SDK - is user "liking" my app?
body: <p>I have two things:
   - how to do: using PHP SDK for Facebook check that user is liking my app?</p>
  
  <p>I need this because client want it.</p>
  
  <pre><code> $isLike = /* Code to check this */
  
  if ($isLike){
  
  //if user like my app
  }else{
  
   //if not
  
   include 'generate.php';
  }
  </code></pre>
  
  <p>And what I should ask this question in "valid" english?</p>