在Asp.Net中显示进度条

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Threading;


public partial class JinDuTiao : System.Web.UI.Page
...{
    protected void Page_Load(object sender, EventArgs e)
    ...{
        Response.Write("<div id='mydiv' >");
        Response.Write("_");
        Response.Write("</div>");
        Response.Write("<script>mydiv.innerText = '';</script>");
        Response.Write("<script language=javascript>;");
        Response.Write("var dots = 0;var dotmax = 10;function ShowWait()");
        Response.Write("{var output; output = '正在装载页面';dots++;if(dots>=dotmax)dots=1;");
        Response.Write("for(var x = 0;x < dots;x++){output += '·';}mydiv.innerText =　output;}");
        Response.Write("function StartShowWait(){mydiv.style.visibility = 'visible'; ");
        Response.Write("window.setInterval('ShowWait()',1000);}");
        Response.Write("function HideWait(){mydiv.style.visibility = 'hidden';");
        Response.Write("window.clearInterval();}");
        Response.Write("StartShowWait();</script>");
        Response.Flush();
        Thread.Sleep(10000);


    }
}