code: function() {
              var width = self.innerWidth,  // Safari
                  mode = document[COMPAT_MODE];
              
              if (mode || isIE) { // IE, Gecko, Opera
                  width = (mode == CSS1_COMPAT) ?
                          documentElement.clientWidth : // Standards
                          document.body.clientWidth; // Quirks
              }
              return width;
          }
docs: Returns the current width of the viewport.
  @method getViewportWidth
  @return {Int} The width of the viewable area of the page (excludes scrollbars).