text: define([
      "skylark-langx/langx",
      "skylark-domx-geom",
      "./fx",
      "./slideDown",
      "./slideUp"
  ],function(langx,geom,fx,slideDown,slideUp) {
  
      /*   
       * Display or hide an element with a sliding motion.
       * @param {Object} elm  
       * @param {Number or String} duration
       * @param {Function} callback
       */
      function slideToggle(elm, duration, callback) {
  
          // if the element is hidden, slideDown !
          if (geom.height(elm) == 0) {
              slideDown(elm, duration, callback);
          }
          // if the element is visible, slideUp !
          else {
              slideUp(elm, duration, callback);
          }
          return this;
      }
  
      return fx.slideToggle = slideToggle;
  });