Popup windows

I was going through this website http://www.ziggystudio.com/v1/main.htm (great site by the way) and I was wondering how does he/she create those popup windows that have a perfect size around the images o swfs. I doubt that it’s done manually because it looks to great. I would really appreciate the clarification. Thanks!

better titles please, and search this site and the tutorials for "popup windows "…has been answered like once a day…