javascript - How to check IF user has ALREADY liked the facebook page -

i used facebook after liked redirection code . cant find solution user liked. if user liked redirect page.

the code

<script type="text/javascript">         window.fbasyncinit = function() {             fb.init({appid: 'xxxxxxxxxxxxxxxxx',              status: true,              cookie: true,              xfbml: true             });             fb.canvas.setsize({ width: 400, height: 80 });              fb.event.subscribe('edge.create',                 function(response)              {                     alert('thank you');                     // put redirect code here eg                     window.location = "http://www.example.com/facebookautoredirect.asp";              }             );             **if liked              {              window.location = "http://www.example.com/facebookautoredirect.asp";             }**          };          //load sdk asynchronously         (function() {             var e = document.createelement('script'); e.async = true;                 e.src = document.location.protocol +                   '//connect.facebook.net/tr_tr/all.js';                 document.getelementbyid('fb-root').appendchild(e);         }());     </script> 

best regards

that´s possible if authorize user (you need facebook app that), "user_likes" permission > after can read likes , check if liked specific page.

facebook docs user login: https://developers.facebook.com/docs/reference/javascript/fb.login/

careful that, cannot open without user interaction:

calling fb.login results in js sdk attempting open popup window. such, method should called after user click event, otherwise popup window blocked browsers.

or php sdk: https://developers.facebook.com/docs/reference/php/facebook-getloginurl/