The popup on click in a medium-sized window at http://highslide.com/ is javascript and you can download the codes from that page. I don't think you will do anything similar without javascript but you can do popups on hover with pure CSS (no javascript) but as soon as you move the mouse away you lose the popup.
See
http://www.dynamicdrive.com/style/cs...-image-viewer/
and
http://www.wickham43.supanet.com/tut...verpopups.html which shows text which produces a popup text box on hover and you can alter the popup size. It's designed as a link but you can disable the link by adding nogo or thumb in the link
.........<a href="nogo">..........
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.