css picture pop ups again - any way to fade them in?

[snow patrol]

http://www.mathofbirds.com/williamtest1/wiv4.html

as you can see, i have the pictures snap up when the user puts their mouse over the thumbnail. However, would it be possible to fade the picture in or something?

Or would i need to resort to using flash or something?

Many thanks.

 

[snow patrol]

interesting. Thanks for the link.

I will try to get my teeth sunk into it, but to be honest i'm not quite sure how exactly i should edit my style sheet so that only the larger image fades in, and not the thumbnails.