how to make a popup window be a hyperlink itself

I'm making a picture gallery with thumbnails that, once clicked, open into popups. I would like to make the popups themselves be hyperlinks. This is for a web store and I would like to have the popups hyperlink back to the product pages. Could anyone explain how this is done.

Thanks,
Francis

These pop-ups will contain the larger image? why not make the image itself a link? <a href="#"><img src="#"></a>