Hide panel in repeater

I'm thinking how to hide a panel in a repeater with a button also in the repeater? Does anyone here know how? Here is a peace of code (sorry the code tag i forgot) to see what I mean:

<asp:Repeater id="Repeater1" runat="server">
 <ItemTemplate>
  <strong>
   <asp:Button id="Button1" runat="server" Text="Button"></asp:Button><br>
   <%# DataBinder.Eval(Container.DataItem, "Category") %>
  </strong>
  <br>
  <asp:Panel id="Panel1" runat="server">
   <asp:Repeater id="Repeater2" runat="server" datasource='<%# Container.DataItem.Row.GetChildRows("myrelation") %>'>
    <ItemTemplate>
     <%# Container.DataItem("title") %>
     <br>
    </ItemTemplate>
   </asp:Repeater>
  </asp:Panel><br>
  <br>
 </ItemTemplate>
</asp:Repeater>