PHP 点击链接更新数据库,返回值

<a href="javascript:void(0)" title="收藏" class="c-p-n-txt" id='collection_user'>收藏</a>

<script>//收藏
$('#collection_user').on('click', function(){
        var url = encodeURI("add_js_note.php?action=collection&name=$tt&id_id=$id");
            //Ajax获取
            $.post(url, {}, function(str){
              layer.msg(str);
            });
});