return Element.classNames(element).add(className); 
Element.classNames(element).add(className); return element; 
  addClassName: function(element, className) {    if (!(element = $(element))) return;    return Element.classNames(element).add(className);  },
6445	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/6445/81ea0800bc8ad92d491743716cd489cad7333723/prototype.js/buggy/vendor/rails/actionpack/lib/action_view/helpers/javascripts/prototype.js