ASP.NET AJAX调用 WebService

同事的代码，帮忙修改的，为了实现页面跳转回来后，状态的保持，Service 使用了Session。

 主要的JS  
  $.ajax({
            url: "/ws/StaffInfo.asmx/Note",//路径/方法
            type: "POST",
            contentType: "application/json",
            data: "{id:'" + id + "',sex:'" + sex + "',dep:'" + dep + "',sql:'" + sql + "',page:'" + page + "'}",
            dataType: "json",
            success: function (res) {
                //var th = res.d;
                //alert(th);
                window.open("AddStaffInfo.aspx?id=" + getid + "", "_self");
            },
            error: function (XMLHttpRequest, textStatus, errorInfo) {
                alert("请求失败");
            }
            //error: function (data) {
            //    alert("请求失败");
            //}
        });
    
       //此处使用 Session，必须加的特性
       [WebMethod(EnableSession = true)]
        public string Note(string id, string sex, string dep, string sql,string page)
       {
                Session["WebServiceStaffIsopen"] = true;
                Session["WebServiceStaffId"] = id;
                Session["WebServiceStaffSex"] = sex;
                Session["WebServiceStaffDep"] = dep;              
                Session["WebServiceStaffPage"] = page;
         
                string s = Microsoft.JScript.GlobalObject.unescape(sql);
                Web.StaffInfo.Id = id;
                Web.StaffInfo.Sex = sex;
                Web.StaffInfo.Dep = dep;
                Web.StaffInfo.Sql = s;
                Web.StaffInfo.Index = page;
                Web.StaffInfo.Isopen = true;
                if (s.Trim().ToLower() == "true")
                {
                    Web.StaffInfo.Sql = "1=1";
                    Session["WebServiceStaffSql"] = "1=1";
                }
                else
                {
                    Web.StaffInfo.Sql = s;
                    Session["WebServiceStaffSql"] = s;
                }
                return s + id + sex + dep + page;

        }