When using AJAX calls to rails methods, send CSRF token to validate the request

ajax-csrf-rails.js

var csrf_token = $('meta[name=csrf-token]').attr('content');

$("body").bind("ajaxSend", function(elm, xhr, s){
  if (s.type == "POST") {
    xhr.setRequestHeader('X-CSRF-Token', csrf_token);
  }
});