Google maps div will always show on page even when panel visible = false??

hi,
I am using the solution in this tutorial to show google maps on my page.
http://aspsnippets.com/Articles/ASPNet-Populate-Google-Maps-V3-with-Multiple-Markers-using-Address-Latitude-and-Longitude-values-stored-in-database.aspx
there are 4 linkbuttons like so on my aspx - each linkbutton corresponds to a panel
on the page and each one has a datalist within.

<li><asp:LinkButton ID="LinkButton1" runat="server"         onclick="LinkButton1_Click">Playlist</asp:LinkButton></li> <li>Reviews</li> <li><asp:LinkButton ID="LinkButton4" runat="server" onclick="LinkButton4_Click">Sample</asp:LinkButton></li>         <li><asp:Lin ...