如何遍历RadioButtonList控件并为子项添加JS验证

后台：

 protected void Page_Load(object sender, EventArgs e)
        {
            //Session["RegistrationTitle"].ToString();//标题
            //Session["Folder"].ToString();//文件夹名
            if (Session["ResultList"]!=null)
            {
                Session["ResultList"].ToString();//字段信息
            }
          
            if (!IsPostBack)
            {
                //bind control type
                this.rbl_Tyle.DataSource = Enum.GetNames(typeof(Common.InfoControlType));
                this.rbl_Tyle.DataBind();
                this.cbl_Validators.DataSource = Enum.GetNames(typeof(Common.ValidatorType));
                this.cbl_Validators.DataBind();
            }
           //遍历RadioButtonList控件

            foreach (ListItem item in rbl_Tyle.Items)
            {
                item.Attributes.Add("onclick", "validateRadioButtonList(this)");
            }
        }

前台：

<asp:RadioButtonList ID="rbl_Tyle" runat="server" RepeatDirection="Horizontal"></asp:RadioButtonList>
                <asp:Label ID="LabType" runat="server" Text="" ForeColor="Red"></asp:Label>

   JS脚本

     function validateRadioButtonList(e) {
            //            var obj = e.value;
            alert(e.value);
            document.getElementById("<%=LabType.ClientID%>").innerHTML = "";
        }