正则表达式验证

   string bb = b.ToString();
           var regu = "^[0-9]*$";
            Regex re=new Regex (regu);
            if (!re.IsMatch(bb))
            {
                Page.RegisterClientScriptBlock("k", "<script>alert('订单数量输入有误，请查看！')</script>");
                return;
            }