code: function() {
              var height = self.innerHeight, // Safari, Opera
                  mode = document[COMPAT_MODE];
          
              if ( (mode || isIE) && !isOpera ) { // IE, Gecko
                  height = (mode == CSS1_COMPAT) ?
                          documentElement.clientHeight : // Standards
                          document.body.clientHeight; // Quirks
              }
          
              YAHOO.log('getViewportHeight returning ' + height, 'info', 'Dom');
              return height;
          }
docs: Returns the current height of the viewport.
  @method getViewportHeight
  @return {Int} The height of the viewable area of the page (excludes scrollbars).