if ((this.usertxt.Text == "") || (this.pwdtxt.Text == ""))
        {
            Response.Write("<script>alert('用户名、密码不能为空');</script>");
        }
        else
        {
            string ConnectionString = "server=localhost;database=user;uid=sa;pwd=123456";
            SqlConnection con = new SqlConnection(ConnectionString);
            con.Open();
            string name = this.usertxt.Text.ToString();
            string pass = this.pwdtxt.Text.ToString();
            string cmdtxt = "select * from vip where user='" + name  + "' and pwd ='" + pass + " '";
            
            SqlCommand cmd = new SqlCommand(cmdtxt, con);
            int red = Convert.ToInt32(cmd.ExecuteScalar());
            if (red > 0)
            {
                Session["admin_name"] = this.usertxt.Text.ToString();
                Response.Redirect("hello.aspx");
            }
            else
            {
                Response.Write("<script>alert('请与管理员联系！');</script>");

            }
        }