asp.net登陆问题

Question

用asp.net开发的一个系统
要登陆很多次才能登陆成功
退出也是要退很多次才能退出成功
登陆代码：
 protected void Button1_Click(object sender, EventArgs e)
    {
        string uname = this.txtuname.Text;
        string upass = MD5.EncryptPassword(this.txtupass.Text, "MD5");
        Db_user user = Db_userManager.Login(uname, upass);
        if (user != null && user.Ustatus == 1)
        {
            //记住我的名字
            if (!string.IsNullOrEmpty(Request["jizhuwo"]))
            {
                HttpCookie Cookie = CookiesHelper.GetCookie("UserInfo");
                if (Cookie == null)
                {
                    Cookie = new HttpCookie("UserInfo");
                    Cookie.Values.Add("uName", uname);
                    Cookie.Values.Add("uPass", upass);
                    //设置Cookie过期时间
                    Cookie.Expires = DateTime.Now.AddDays(7);
                    CookiesHelper.AddCookie(Cookie);
                }
                else if (Cookie.Values["uName"].Equals(uname) && Cookie.Values["uPass"].Equals(upass))
                {
                    CookiesHelper.SetCookie("UserInfo", "uName", uname);
                    CookiesHelper.SetCookie("UserInfo", "uName", upass);
                }            }
            Session["USER"] = user;
            Response.Redirect("~/Default.aspx");
        }
        else if (user != null && user.Ustatus == 0)
        {
            this.ClientScript.RegisterStartupScript(this.Page.GetType(), "操作提示", "alert('您好您的账号还没有激活');", true);
        }
        else
        {
            this.ClientScript.RegisterStartupScript(this.Page.GetType(), "操作提示", "alert('您输入的用户名或密码错误，请重新输入');", true);
        }    }
 //退出代码：
    protected void LbExit_Click(object sender, EventArgs e)
    {
        Session.Remove("USER");
        string cookname;
        HttpCookie hc;
        int k = Request.Cookies.Count;
        for (int i = 0; i < k; i++)
        {
            cookname = Request.Cookies[i].Name;
            hc = new HttpCookie(cookname);
            hc.Expires = DateTime.Now.AddDays(-1);
            Response.Cookies.Add(hc);
        }
        Response.Redirect("~/Default.aspx");
    }
哪位高手指点一下

Answer 1

把电cookies清楚一下再试试？！

Answer 2

单步跟踪
 protected void ImgbtnClick(object sender, ImageClickEventArgs e)
        {
            if (Page.IsValid)
            {
                Sys_User user = SysUserBLL.SelectByUserId(Util.FormatInputStr(this.txtUser.Text));
                if (user != null)
                {
                    if (!user.PassWord.Equals(txtPwd.Text.Trim()))
                    {
                        new Jscript(this, "您输入的密码不对！").Show();
                        return;
                    }
                    else
                    {
                  
                        Session.Add("UserId", user.UserId);
                        Session.Add("UserName", user.UserName);
                   
                        this.Response.Write("<script language='javascript'>window.open(‘index.aspx','_self')</script>");
                    }
                }
                else
                {
                    new Jscript(this, "您没有任何权限！").Show();
                     return;
                }
            }
        }

Answer 3

http://forum.csdn.net/PointForum/ui/scripts/csdn/Plugin/003/onion/52.gif