asp.net中添加数据ajax读取不到新数据，请高手指教
--插入数据方法
   
  function insertUser()
  {
  $.get("inseruser.ashx",{uname:$("#uname").val(),upwd:$("#upwd").val(),uage:$("#uage").val(),usex:$("#usex").val()},function(msg){
  $("#aaa").text(msg);
  getdata3();
  });
   
   
  }
   
---得到所有信息方法 
function getdata3()
  {
   
   
  $.getJSON(
  "UserAllHandler.ashx",
   
  function(data){
   
  var table=$("<table align=center width=60% border=1>"+
  "<tr>"+
  "<td>编号</td>"+
  "<td>姓名</td>"+
  "<td>年龄</td>"+
  "<td>密码</td>"+
  "</tr></table>");
   
  var user=data;
  //document.write(user.length);
  for(var i=0;i<user.length-1;i++)
  {
  $("table").empty();
  u=user[i];
  var row=$("<tr></tr>");
  //document.write(key);
   
  var td0=$("<td></td>");
  td0.text(i+1);
   
  var td1=$("<td></td>");
  td1.text(u.uname);
  var td2=$("<td></td>");
  td2.text(u.upwd);
  var td3=$("<td></td>");
  td3.text(u.uage);
   
  td0.appendTo(row);
  td1.appendTo(row);
  td2.appendTo(row);
  td3.appendTo(row);
   
   
  row.appendTo(table);
   
   
  }
  table.appendTo($("#dd"));
  },"json");
   
  } 
------------UserAllHandler.ashx文件
<%@ WebHandler Language="C#" Class="UserAllHandler" %>

using System;
using System.Web;
using System.Data;
using System.Text;

public class UserAllHandler : IHttpHandler {
  Users user = new Users();
  DataSet ds = new DataSet();
  public void ProcessRequest (HttpContext context) {
  context.Response.ContentType = "text/plain";
  //context.Response.Write("Hello World");
   
  context.Response.Clear();
   
  this.ds = user.userSelectAll();