1 banner at a time in banner_box_all

As above - how do we do this?
Both other side banner boxes have random photos flashing up in them, so I am trying to use the "banner box all" to show a sponsor's banner with a link.
All working ok there, but it shows every banner from the group nominated at once - I need to show them one at a time!
Any ideas?
Have compared the banner box template files but as I'm new at this whole thing...no great result! On the plus side I have found out a variety of ways to make my homepage blank or have a big gap where the box and its contents should be! :D lol.

The Banners All sidebox is specifically designed to show, at the same time, all banners that are setup for this sidebox ...

The other two banner boxes only show 1 banner at a time ...

If you need a third banner box that only shows 1 banner at a time, you could clone the Banner Box 2 and use that instead ...

Ajeh:

The Banners All sidebox is specifically designed to show, at the same time, all banners that are setup for this sidebox ...

The other two banner boxes only show 1 banner at a time ...

If you need a third banner box that only shows 1 banner at a time, you could clone the Banner Box 2 and use that instead ...

I had a crack at that, but obviously didn't cover everything I needed to.
I'm guessing it's not just a matter of copying banner box 2's php file and calling it banner box all, huh? wasn't sure what I would need to change internally in that particular cloned file...
If it's not too much of a time waster for you, could you let me know the best way to clone the banner box pls?
Many thanks.