window.addEvent('domready', function() {
  var accordion = new Accordion('h4.atStart', 'div.atStart', {
	opacity: false,
	onActive: function(toggler, element){
		toggler.setStyle('color', '#ff3300');
	},
 
	onBackground: function(toggler, element){
		toggler.setStyle('color', '#fff');
	}
}, $('contenu'));
});