code: function _ready() {
           if (!document.body) {
              return window.setTimeout(_ready, 50);
           }
           getImageProgress = gamejs.image.preload(RESOURCES);
           try {
              getMixerProgress = gamejs.audio.preload(RESOURCES);
           } catch (e) {
              gamejs.debug('Error loading audio files ', e);
           }
           window.setTimeout(_readyResources, 50);
        }
docs: 2.