I have attached the sourcecode - as you can see it is very lean.
You will need to play with the CSS and HTML to make it fit your site, but that is very easy - also if you want to stick some fancy backgrounds in etc.
The reason the code can be so lean is beasue it does not have to cater for every little thing.
Thumbnails go in the thumbs folder
Photos go in the photos folder ... the rest is done.
I have also included the right and left arrows for the slider - these can be changed to any images and positioned by playing with the CSS ...
Hope it helps