[Zope] open image in a fitted new window

Dears, I was wondering how to once clicking on a image (thumbnail) I would get the full-size image in a fitted new window, without buttons, address field etc. I can realise how to do it with javascript but I don't know, if it's the only way, how to integrate javascript in a zpt. A example/tutorial would be very welcome so. If it can be done without javascript, just with zope tools, that would be very appreciated. Many thanks in advance. Cheers, Alan