docs: function getStyle(dom, name, defaultValue) {
      try {
        if (window.getComputedStyle) {
          return window.getComputedStyle(dom, null)[name];
        }
        return dom.currentStyle[name];
      } catch (e) {
        if (!Util.isNil(defaultValue)) {
          return defaultValue;
        }
        return null;
      }
    }