rem: element = $(element); Element.removeClassName(element, className); element.className += ' ' + className; 
add: if (!(element = $(element))) return; return Element.classNames(element).add(className); 
context:   addClassName: function(element, className) {    element = $(element);    Element.removeClassName(element, className);    element.className += ' ' + className;  },
meta: 60	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/60/3f913f897829fb026ef98df2d57f8da94ee5339d/prototype.js/buggy/public/javascripts/prototype.js