ASP.Net ต้องการทำ pop up GridView แต่ พอเลือกอันที่ 2 ไม่ได้

<div id="dialog" class="web_dialog">
    <asp:ScriptManager ID="ScriptManager1" runat="server" />
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
            <ContentTemplate>
    <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox> 
                <asp:Button ID="Button2" runat="server" Text="Button" onclick="Button2_Click" />
                <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False">
         <Columns>
        <asp:TemplateField HeaderText="เลือก" >
		    <ItemTemplate>
                <div id="brands">

                    <input id='<%# DataBinder.Eval(Container, "DataItem.emp_name_thai") %>' name="brand" type="radio"  value='<%# DataBinder.Eval(Container, "DataItem.emp_department") %>' />
                </div>
            </ItemTemplate>    
	    </asp:TemplateField>
	    <asp:TemplateField HeaderText="ชื่อ" >
		    <ItemTemplate>
			    <asp:Label id="lblemp_name_thai" runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.emp_name_thai") %>'></asp:Label>
		    </ItemTemplate>    
	    </asp:TemplateField>
        <asp:TemplateField HeaderText="แผนก" >
		    <ItemTemplate>
			    <asp:Label id="lblemp_department" runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.emp_department") %>'></asp:Label>
		    </ItemTemplate>    
	    </asp:TemplateField>
        

    </Columns>
    </asp:GridView>
     </ContentTemplate>
   </asp:UpdatePanel>  
    <input id="btnSubmit" type="button" value="Submit" />
      
</div>

<script type="text/javascript">

        $(document).ready(function () {
            $("#btnShowSimple").click(function (e) {
                ShowDialog(false);
                e.preventDefault();
            });

            $("#btnShowModal").click(function (e) {
                ShowDialog(true);
                e.preventDefault();
            });

            $("#btnClose").click(function (e) {
                HideDialog();
                e.preventDefault();
            });

            $("#btnSubmit").click(function (e) {
                var brand = $("#brands input:radio:checked").val();
                document.getElementById("TextBox1").value = brand;
                HideDialog();
                e.preventDefault();
            });

        });

        function ShowDialog(modal) {
            $("#overlay").show();
            $("#dialog").fadeIn(300);

            if (modal) {
                $("#overlay").unbind("click");
            }
            else {
                $("#overlay").click(function (e) {
                    HideDialog();
                });
            }
        }

        function HideDialog() {
            $("#overlay").hide();
            $("#dialog").fadeOut(300);
        } 
        
</script>