$$('#days-menu a').addEvent('click',function(){		
	$$('#days-menu a').setStyle('background-position','center 4px');
	var selected_day = this.getAttribute("id");
	$(selected_day).setStyle('background-position','center -25px');
	$$('.menu ul').setStyle('display','none');
	$('day_' + this.getAttribute("id")).setStyles({'display':'block','top':'0'});
});