Behaviour.register({ 'div.confirmedpassword' : { initialize: function() { var rules = {}; rules['#'+this.id+' .showOnClick a'] = {onclick: function(e) { this.toggle(); Event.stop(e); }.bind(this)}; Behaviour.register(rules); this.toggle(); }, toggle: function() { var containers = $$('.showOnClickContainer', this); if(!containers.length) return false; var container = containers[0]; Element.toggle(container); var hiddenField = $$('input.hidden', this)[0]; hiddenField.value = (Element.visible(container)); } } });