I want to have 1 large image with a row of thumbnails below. Click any small image, replace the large one with large version of that thumbnail.

I was gaily thinking I could do this in Dreamweaver but now suspect not ...

I'm not expecting anyone to give me chapter and verse on how to do it - just to point me in the right direction, please.

Sorry to waste your time guys I found the answer. There's a good youtube video if any one else doesn't know about this, and it's easy in Dw using Behaviours.