Ecshop中的ajax+json

js代码部分
/* 订单查询 */
function orderQuery()
{
  var order_sn = document.forms['ecsOrderQuery']['order_sn'].value;

  var reg = /^[\.0-9]+/;
  if (order_sn.length < 10 || ! reg.test(order_sn))
  {
    alert(invalid_order_sn);
    return;
  }
  Ajax.call('user.php?act=order_query&order_sn=s' + order_sn, '', orderQueryResponse, 'GET', 'JSON');
}

/*返回函数*/
function orderQueryResponse(result)
{
  if (result.message.length > 0)
  {
    alert(result.message);
  }
  if (result.error == 0)
  {
    var div = document.getElementById('ECS_ORDER_QUERY');
    div.innerHTML = result.content;
  }
}

//php部分
if (!empty($_REQUEST['act']) && $_REQUEST['act'] == 'gotopage')
{
    include('includes/cls_json.php');

    $json   = new JSON;
    $res    = array('err_msg' => '', 'result' => '');

    $goods_id   = isset($_REQUEST['id']) ? intval($_REQUEST['id']) : 0;
    $page    = (isset($_REQUEST['page'])) ? intval($_REQUEST['page']) : 1;
.....逻辑代码部分

}

die($json->encode($res));