jquery ajax json操作

ajax

$.ajax({
            type : "get",
            async: true,
            url : url,
            dataType : "json",
            success : function(data){
                if(data == 1){
                    $('#more').html('没有更多评论!').unbind('click');
                    return false;
                }
                $.each(data,function(i,element){
                    var nickname = element.nickname;
                    var content = element.content;
                    var time = element.time;
                    var imgpath = element.imgpath;
                    var info = $('<li class="comment"><div class="left"><img src="'+imgpath+'"></div><div class="right"><div>'+nickname+'</div><div></div>'+content+'</div></li><hr>');
                    $('#contentList').append(info);
                });
                var now = parseInt($('#last').val()) + 2;
                $('#last').val(now);
            },
            error:function(){
                console.log('fail');
            }
        });

php页面

$query=mysql_query("select * from comment order by id desc limit $last,$amount");
$flag = false;
while ($row=mysql_fetch_array($query)) {
    $flag = true;
    $sayList[] = array(
        'id'=>$row['id'],
        'nickname'=>$row['nickname'],
        'content'=>$row['content'],
        'imgpath'=>$row['imgpath'],
        'time'=>$row['time']
      );
}
if($flag){
    echo json_encode($sayList);
}else{
    echo true;
}