You could as well use the multi view and a couple of views inside. By doing this you can use a button control to choose which view (panel) is to be displayed. The code below will toggle between two views containing two image tags.
ASP.NET Form (HTML)
<div>
<asp:Button ID="Button1" runat="server" Text="Button" />
</div>
<div>
<asp:MultiView ID="MultiView1" runat="server" ActiveViewIndex="0">
<asp:View ID="View1" runat="server">
<imgage = "my picture"> //add image tage here
</view>
<asp:View ID="View2" runat="server">
<imgage = "your picture"> //add image tage here
</view>
</asp: Multiview>
</div>
CODE BEHIND
Private button click toggleImageView
If multiview1.ActiveViewIndex=0 then
multiview1.ActiveViewIndex=1
ElseIf
multiview1.ActiveViewIndex=1 then
multiview1.ActiveViewIndex=0
EndIf
You may also use a list box to select which view to display on the fly like this
But note that your control o select which view to be displayed should be outside the multiview control and also be rendered on page load
<asp:DropDownList ID="DropDownList1" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged"
runat="server" AutoPostBack="True">
<asp:ListItem Value="0">View 1</asp:ListItem>
<asp:ListItem Value="1">View 2</asp:ListItem>
</asp:DropDownList><br />