function order(fn) {
          if (document.readyState != 'loading') {
            fn();
          } else {
            document.addEventListener('DOMContentLoaded', fn);
          }
        }

        order(function() {
          var message = document.getElementById("call-us");

          var show = function() {
            message.classList.remove("hide");
            message.classList.remove("bounceOutLeft");
            message.classList.add("bounceInLeft");
          };

          var hide = function() {
            message.classList.remove("bounceInLeft");
            message.classList.add("bounceOutLeft");
            setTimeout(function() {
              message.classList.add("hide");
            }, 500);
          };

          var closeButton = document.getElementById("close-button");
          closeButton.addEventListener("click", function() {
            if (message.classList.contains("hide")) {
              show();
            } else {
              hide();
            }
          });
        });