$(function(){ 
  $(".acc").each(function(){ 
    $("li > span.year", this).each(function(index){ 
      var $this = $(this); 
 
      if(index > 0) $this.next().hide(); 
 
      $this.click(function(){ 
		var params = {height:"toggle", opacity:"toggle"}; 
        $(this).next().animate(params).parent().siblings() 
          .children("ul:visible").animate(params); 
        return false; 
      }); 
    }); 
  }); 
});