function() {
          if ((cachedWidth = element.offsetWidth) != lastWidth || (cachedHeight = element.offsetHeight) != lastHeight) {
              dirty = true;

              lastWidth = cachedWidth;
              lastHeight = cachedHeight;
          }
          reset();
        }
function() {
          if ((cachedWidth = element.offsetWidth) != lastWidth || (cachedHeight = element.offsetHeight) != lastHeight) {
              dirty = true;

              lastWidth = cachedWidth;
              lastHeight = cachedHeight;
          }
          reset();
        }
function ( ) { if ( ( cachedWidth = element . offsetWidth ) != lastWidth || ( cachedHeight = element . offsetHeight ) != lastHeight ) { dirty = true ; lastWidth = cachedWidth ; lastHeight = cachedHeight ; } reset ( ) ; }
useful to not query offsetWidth twice
useful to not query offsetWidth twice