databound images swap thumbnail / larger image

 I have:
I want to make it so that if someone clicks on one of the thumbnails then the larger version is displayed.
 I was thinking a possibility of doing this might be to have an array and the 1st one in the array is the big image.
 If someone clicks on the thumbnail it reorders the array so that that image goes to the top of the array.
 Is something like that possible?
 I suppose javascript is also a possibility although I'm not well versed on it.

Thanks Andy.

<div class="detailsleftcol">
        <div class="detailsimagebig">
            <asp:Image ID="Image2" runat="server" ImageUrl='~/images/properties/<%# Bind("propertyImageId") %>.<%# Bind("imageFormat") %>' Width="380px" />
 &nb ...