I think we could do that, but you have a bigger error that you should fix, first.
If I click on the >> arrow at the right of the thumbnails and then click on any thumbnail, I get a SPRY error message. Should you figure that bug out, first?
But in the meantime, another problem you have is that ancient ancient DreamWeaver code in there. That stuff is so old, it creaks. Was used when computers still were larger than trucks. (Oh, okay....slight exaggeration.)
Pretty much you should get rid of anything that starts with "MM_".
And your code is FIGHTING itself!!!
You have this:
ONE of those onclicks needs to go! But better would be to scrap *all* MM_ stuff.
<a onclick="MM_affectAppearFade( ... ) ...>
<img ... onclick="MM_swapImage( ... ) ...>
Ahh...I figured out why you get the SPRY error I noted!!!
Your large image is
Yet in one of the two sliding panels, all the onclick's refer to
<img id="country_1" ...>
and of course there is no such ID as "city_1", so *KABLOOEY*.
<a onclick="MM_affectAppearFade('city_1', ... ) ...>
<img ... onclick="MM_swapImage('city_1', ... ) ...>
Anyway, fix the basic problems first, then let's talk about next/previous.
And if AT ALL possible, stop using DreadWalker. DuckWaster would have been better named "Nigthmare Weaver".