Is anybody here familiar with greybox? (http://orangoo.com/labs/GreyBox)

I'm having some trouble with something that should be really basic... I think it's the structure of my links in my <a> tag:

My greybox scripts are in: http://shrutishah.net/greybox/
The images I want are in: http://shrutishah.net/greybox/portfolio/

And my code for displaying the full image is:
Code:
<a href="greybox/portfolio/dreamscape.jpg" rel="gb_image[]"
title="Dreamscape">
<img src="greybox/portfolio/dreamscape-thumb.jpg" border="0"/>
</a>
Does anybody know what's going on? I think it's just that the link url is wrong, but I've tried as many combinations as I can think of and I just can't get it.