Login with Facebook API V2

<title>Facebook Login JavaScript Example</title>
<meta charset="UTF-8">
<script>
 
window.fbAsyncInit = function() {
  FB.init({
    appId      : '572516629527309',
    cookie     : true,  // enable cookies to allow the server to access
                        // the session
    xfbml      : true,  // parse social plugins on this page
    version    : 'v2.1' // use version 2.1
  });
};
(function(d, s, id) {
  var js, fjs = d.getElementsByTagName(s)[0];
  if (d.getElementById(id)) return;
  js = d.createElement(s); js.id = id;
  js.src = "//connect.facebook.net/en_US/sdk.js";
  fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));
 
function fb_login(){
  FB.login(function(response) {
      if (response.authResponse) {
          console.log('Welcome!  Fetching your information.... ');
          //console.log(response); // dump complete info
          access_token = response.authResponse.accessToken; //get access token
          user_id = response.authResponse.userID; //get FB UID
 
          FB.api('/me?fields=id,name,friendlists', function(response) {
              user_email = response.email; //get user email
              console.log(response);
              alert(user_email);
        // you can store this data into your database
          });
 
      } else {
          //user hit cancel button
          console.log('User cancelled login or did not fully authorize.');
 
      }
  }, {
      scope: 'publish_stream,email,read_friendlists'
  });
}
</script>
 
 
 
  <a href="#" onclick="return fb_login();"> 
    <img src="http://www.myclientpage.com/images/fb_login.gif">
  </a>
  <div id="status"></div>