如何使用Label绑定数据库记录并在C＃ASP.NET中的Ajax模型弹出窗口中显示

我的数据库记录与Label正确绑定，但未在Ajax模式弹出窗口中显示。如何使用Label绑定数据库记录并在C＃ASP.NET中的Ajax模型弹出窗口中显示

ASPX代码：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="PopUp.aspx.cs" Inherits="PopUp" %> 

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="asp" %> 

<!DOCTYPE html> 

<html xmlns="http://www.w3.org/1999/xhtml"> 
<head runat="server"> 
    <title></title> 
    <style type="text/css"> 
    .modalBackground 
    { 
     background-color: Black; 
     filter: alpha(opacity=90); 
     opacity: 0.4; 
    } 
    .modalPopup 
    { 
     background-color: #FFFFFF; 
     border-width: 3px; 
     border-style: solid; 
     border-color: black; 
     padding-top: 10px; 
     padding-left: 10px; 
     width: 300px; 
     height: 140px; 
    } 
</style> 

</head> 
<body> 
    <form id="form1" runat="server"> 
    <div> 
    <asp:Label ID="Label1" runat="server"></asp:Label> 
    <asp:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server"> 
</asp:ToolkitScriptManager> 
      <asp:UpdatePanel ID="UpdatePanel2" UpdateMode="Conditional" runat="server"> 
      <ContentTemplate> 
       <asp:Timer ID="Timer1" OnTick="Timer1_Tick" runat="server" Interval="2000"> 
       </asp:Timer> 
      </ContentTemplate> 
     </asp:UpdatePanel> 

     <asp:ModalPopupExtender ID="ModalPopupExtender1" BehaviorID="mpe" runat="server" 
    PopupControlID="pnlPopup" TargetControlID="lbl_ltr_nmbr" BackgroundCssClass="modalBackground" CancelControlID = "btnHide"> 
</asp:ModalPopupExtender> 
     <asp:Panel ID="pnlPopup" runat="server" CssClass="modalPopup" Style="display: none"> 
    <div class="header"> 
     Modal Popup 
    </div> 
    <br /> 
    <div class="body"> 
     <asp:Label ID="lbl_ltr_nmbr" runat="server"></asp:Label> 
     <br /> 
     <asp:Button ID="btnHide" runat="server" Text="Recieve" /> 
    </div> 
</asp:Panel> 
    </div> 
    </form> 
</body> 
</html>

Aspx.cs代码：

using System; 
using System.Collections.Generic; 
using System.Data; 
using System.Data.SqlClient; 
using System.Linq; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 

public partial class PopUp : System.Web.UI.Page 
{ 
    protected void Page_Load(object sender, EventArgs e) 
    { 
     Label1.Text = "Not Refreshed Yet"; 
    } 
    protected void Timer1_Tick(object sender, EventArgs e) 
    { 
     SqlCommand sqlcom = new SqlCommand("CountLetterNumber", DatabaseConnection.OpenConnection()); 
     sqlcom.CommandType = CommandType.StoredProcedure; 
     string ltrnmbr = Convert.ToString(sqlcom.ExecuteScalar()); 
     lbl_ltr_nmbr.Text = "You are Recieved " + ltrnmbr + "new Letter"; 
     ModalPopupExtender1.Show(); 
    } 
}

存储过程：