window.fbAsyncInit = function() {
       FB.init({
       appId      : '291369034600871',
       cookie     : true,
       xfbml      : true,
       version    : 'v2.8'
       });
       FB.getLoginStatus(function(response) {
       statusChangeCallback(response);
       });
       };
      (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'));


     //dropdown
    <ul class="dropdown-menu">
            <li><a class="login" id="loginBtn" data-toggle="modal" data-target="#login-modal" title="">Login</a></li>
          </ul>