Resizing movie in image slide show

i’m trying to make a slide show
under the image is a grey bar that has to resize to every new image width.

i found this kind of effect on this very nice site of a german photographer

http://www.schmidtfoto.de/

i would like to implement this into my design

however … how do you make this kind of thing?

http://www.danda.be/shared/kvd.jpg

i tried to make it by making some changes to a script i found a kirupa, but … i don’t get the right result.

regards
stijn