ajax 调用 webservice 回到 object

ajax 调用 webservice 返回 object
在 ie上调用的结果是这个样子的  
<?xml version="1.0" encoding="utf-8" ?> 
  <string xmlns="http://tempuri.org/">{"":[[{"id":"1","name":"张三","sex":"男","age":"25","depar":"软件部"},{"id":"2","name":"李四","sex":"女","age":"24","depar":"人事部"},{"id":"3","name":"王五","sex":"男","age":"34","depar":"部门经理"},{"id":"4","name":"刘牛","sex":"女","age":"23","depar":"人事部"},{"id":"5","name":"张三","sex":"男","age":"25","depar":"软件部"}]}</string> 

但是 用ajax调用就返回 object 了 无法解析，javascript 代码

JScript code

 $.ajax({                type: "POST",                contentType: "application/json",                url: "WebService1.asmx/Getstaff",                data: "{currPage: '1', tabName: 'staff'}",                dataType: 'json',                success: function (data) {                    alert(data);                }            });

C# code

using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.Services;using DataCall;using System.Data;using System.Text;namespace WebApplication1{    /// <summary>    /// WebService1 的摘要说明    /// </summary>    [WebService(Namespace = "http://tempuri.org/")]    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]    [System.ComponentModel.ToolboxItem(false)]    // 若要允许使用 ASP.NET AJAX 从脚本中调用此 Web 服务，请取消对下行的注释。    [System.Web.Script.Services.ScriptService]    public class WebService1 : System.Web.Services.WebService    {        DAL dal = new DAL();        [WebMethod]        /// <summary>        /// 获取信息        /// </summary>        /// <param name="currPage">当前页页码</param>        /// <param name="showColumn">需要得到的字段</param>        /// <param name="tabName">需要查看的表名</param>        /// <param name="strCondition">查询条件</param>        /// <param name="ascColumn">排序的字段名</param>        /// <param name="bitOrderType">排序的类型 (0为升序,1为降序)</param>        /// <param name="pkColumn">主键名称</param>        /// <param name="pageSize">分页大小</param>        /// <returns></returns>        public string Getstaff(int currPage, string tabName)        {            DataTable dt = dal.GgtSatff(currPage, "*", tabName, "", "id", 0, "id", 5);            string json = DataTable2Json(dt);            return json;        }        #region dataTable转换成Json格式        ///<summary>        /// dataTable转换成Json格式         ///</summary>        ///<param name="dt"></param>        ///<returns></returns>        public static string DataTable2Json(DataTable dt)        {            StringBuilder jsonBuilder = new StringBuilder();            jsonBuilder.Append("{\"");            jsonBuilder.Append(dt.TableName);            jsonBuilder.Append("\":[");            jsonBuilder.Append("[");            for (int i = 0; i < dt.Rows.Count; i++)            {                jsonBuilder.Append("{");                for (int j = 0; j < dt.Columns.Count; j++)                {                    jsonBuilder.Append("\"");                    jsonBuilder.Append(dt.Columns[j].ColumnName);                    jsonBuilder.Append("\":\"");                    jsonBuilder.Append(dt.Rows[i][j].ToString());                    jsonBuilder.Append("\",");                }                jsonBuilder.Remove(jsonBuilder.Length - 1, 1);                jsonBuilder.Append("},");            }            jsonBuilder.Remove(jsonBuilder.Length - 1, 1);            jsonBuilder.Append("]");            jsonBuilder.Append("}");            return jsonBuilder.ToString();        }        #endregion dataTable转换成Json格式    }} 
 

JScript code

 $.ajax({                type: "POST",                contentType: "application/json",                url: "WebService1.asmx/Getstaff",                data: "{currPage: '1', tabName: 'staff'}",                dataType: 'json',                success: function (data) {                    var data = eval("("+msg+")");                    for(i=0;i<data.rows.length;i++)            {                        data.rows[i].id;//这里获取                        data.rows[i].name;                        data.rows[i].sex;                        data.rows[i].age;                        data.rows[i].depar;                    }                }            });
[解决办法]
用IE或者火狐或者google浏览器 调试下. 看下返回的object是什么` 

IE8 F12 调试.