<script type="text/javascript">
    function AddUser() {
        var userName = $("#txtUserName").val();
        var Email = $("#txtEmail").val();
        var dpost = "{action:\"AddUser\",UserName:\"" + userName + "\",Email:\"" + Email + "\"}";
        alert(dpost);
        $.ajax({
            url: "Ajax/UserAjax.aspx",
            data: dpost,
            dataType: "JSON",
            success: function (result) {
                alert(result);
            },
            error: function (XMLHttpRequest, textStatus, errorThrown) {
                alert(XMLHttpRequest.status);
                alert(XMLHttpRequest.readyState);
                alert(textStatus);
            }

        });
    }
</script>
    <input type="text" id="txtUserName" /><br />
    <input type="text" id="txtEmail" /><br />
    <asp:Button ID="btnAdd" runat='server' Text="添加" OnClientClick="AddUser();return false;" />

protected void Page_Load(object sender, EventArgs e)
        {
            if (Request["action"] != null)
            {
                string action = Request.Form["action"].ToString();
                if (action == "AddUser")
                {
                    try
                    {
                        string userName = Request.Form["UserName"];
                        string email = Request.Form["Email"];


                        DataSet dsUser = Application["dsUser"] as DataSet;
                        DataRow drUser = dsUser.Tables[0].NewRow();
                        drUser["userName"] = userName;
                        drUser["Email"] = email;
                        dsUser.Tables[0].Rows.Add(drUser);
                        Application["dsUser"] = dsUser;
                        Response.Write("ok");
                    }
                    catch
                    {
                        Response.Write("Add Error");
                    }
                }
            }
        }