Dynamically swapping images

[MortimerJazz]

Afternoon everyone,

 

Here's the rough layout of a page I'm currently working on - it's a bit like a 'profile' page I suppose:

 

 

Apologies for the rather quick Photoshopping ... but you can see roughly where I am.

 

What I'd like to make happen is to allow visitors to the page to click on Pic2 or Pic3 and have that image swap with the main image, so that the smaller pics can be seen larger.

 

Now the problem is that I somehow need to be able to check which of the three images are currently in the Main Image area, so that I know which two to swap.

 

So my question is, how can I see exactly which picture is currently being displayed in the main image area? And how do I update this each time that one of the smaller images are clicked on.

 

ANY help would be really appreciated!

 

Thanks,