title: Use facebook app Id on multiple domains
body: <p>I had registered a facebook app for my website. And my problem is that I use <strong>single sign on</strong> for my website. </p>
  
  <p>User must login with their facebook account in <strong>www.site1.com</strong>, then they will be redirected to <strong>www.site2.com</strong>.</p>
  
  <p>How can i use the same register app Id on 2 sites for future functions. I want to use facebook javascript sdk to some stuff on <strong>www.site2.com</strong></p>
  
  <p>Thanks for your help. Nice day ! </p>