public void Login()
 {
     if (!FB.IsLoggedIn)
     {
         FB.Login("email,publish_actions,user_friends", LoginCallback);//user_likes,email, "email,publish_actions"
     }
     else
     {
         _socialManager.OnLoginResponse();
         // FB.API("me?fields=id,first_name,last_name", Facebook.HttpMethod.GET, UserCallBack);//"me?fields=id,email,first_name,last_name"
     }
 }