I don't have the exact answer for you. But were I would start is, you should be able to assign states to your thumbnail much in the way you handle them for links. You will have a mouse over and a click state. You would maybe use hotspots if that doesn't work. But you will need to put in the code or scripting that would tell the system when you mouse over the thumb nail to load in a box (could be a table or maybe something like a text box, been a while since I played with dreamweaver) I will attempt to look at it this weekend if I can. Just trying to give you some ideas to play with in the mean time.

I hate that. When I then move the mouse somewhere else, the image changes. I would rather click it, so the image stays.

images with a mouseover making the image appear larger elsewhere. Layers are very easy to use and can fit on top of tables or CSS. Take a look at this and see if this is what you want to do. if so i'll give you a file to follow to do this very easily in dreamweaver.
http://www.mac-designs.co.uk/help/swapimage.html

Hi
Thanks for the reply - yes this is exactly what I want to do - file will be very gratefully received!

thanks

chris cox

Chris Cox, Click on the link again I posted in my previous answer and you can download a tutorial I put together to show you how to do the layers. have fun