protected void btnDoChange_Click(object sender, EventArgs e)
        {
            string userId   = Context.User.Identity.Name;
            string oldpass  = txtOldPass.Text;
            string newpass1 = txtNewPass1.Text;
            string newpass2 = txtNewPass2.Text;

            if (newpass1 != "" && newpass1 == newpass2)
            {
                if (MemberInfo.ChangePassword(userId, oldpass, newpass1))
                {
                    lblResult.Text = "密码修改成功,下次登录请使用新密码";
                }
                else
                {
                    lblResult.Text = "密码修改失败";
                }
            }
        }