How to reference a linkbutton inside gridview

See more:

ASP.NET

WebForms

Gridview

Hi, I am using Modal popup extender to show a panel once I click on Button1 control as seen below. The code works fine.

However, instead of using Button1 control as a target (TargetControlID="Button1"), I want to use another control inside gridview, LbnInternDetail to show detail once a user click on it.

My question, how can I reference <asp:LinkButton button which is located inside a gridview

TargetControlID="GvName.Container(" XXXX ")   // not sure and do not know how 

Please help

<asp:Button ID="Button1" runat="server" Text="fill form" />
    <%--    code from 89 til 100 is modal popup--%>
    <ajaxToolkit:ModalPopupExtender ID="ModalPopupExtender1" runat="server" 
        CancelControlID="btnCancel"
        TargetControlID="Button1" 
        PopupControlID="Panel1">
    </ajaxToolkit:ModalPopupExtender>

    <asp:Panel ID="Panel1" runat="server" CssClass="Popup" align="center" style = "display:none">
        <iframe style=" width: 350px; height: 200px;" id="irm1" src="changePwd.aspx" runat="server"></iframe>
        <br/>
        <asp:Button ID="Button2" runat="server" Text="Close" />
    </asp:Panel>

<asp:TemplateField HeaderText="Name " InsertVisible="false" SortExpression="internName">
    <ItemStyle />
    <ItemTemplate>
        <asp:LinkButton ID="LbnInternDetail"
            OnClick="InternDetail"
            Text='<%# DataBinder.Eval(Container.DataItem,"internName") %>'
            CommandArgument='<%# Eval("internId") %>'
            CommandName="select" 
            ForeColor="#8C4510" runat="server"
        >
        </asp:LinkButton>
    </ItemTemplate>
</asp:TemplateField>

What I have tried:

GvName.Container(" XXXX ")

not sure how