rem: return !values.include(value); 
add: return value != null; 
context:     return this.select(function(value) {      return !values.include(value);    });
meta: 1206	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/1206/81ea0800bc8ad92d491743716cd489cad7333723/prototype.js/clean/vendor/rails/actionpack/lib/action_view/helpers/javascripts/prototype.js