Lightbox caption with paypal button

Hi,

On my homepage at storm3d.com I have 9 thumbnails of my latest sketches and finished designs.
Until recently I simply linked these images to my other blog on which I also sell my designs, http://tribalflashtattoos.blogspot.com.
I discovered a simple script, Lightbox, which is used to overlay images on a webpage, and implemented it to display my canvas prints.
No problem thus far...

Recently I visited a website that also had the Lightbox script, but also included a Paypal button in the caption, so visitors could easily buy the print/photo with a simply click.
It would be really nice to have such an option on my site as well.

It seemed quite easy to make a new button in my Paypal account and copy the html-code in the lightbox "title" code.
Unfortunately it wasn't that easy...
After a few hours of trial and error I discovered this webpage.
I downloaded an adjusted "lightbox.js" file and copied it to my server.
Then I changed the "title" tag in a "caption" tag and voila!

Here's a picture of the result on my homepage: