XML driven menu help

I’ve got a bit of a quandary on my hands and I was hoping some kind soul would have a simple solution to my problem.

I’m trying to create an XML driven menu for my portfolio site. I’m basing the code concept off Senocular’s tutorial on this site, but I’m basing the aesthetic/operational idea off portfolio menus such as those seen on iso50.com and basically every other portfolio site that uses small thumbnails as icons to present larger versions of the work.

Functionally, I think I’ve got it down (it’s basically the tutorial code with the submenu functions stripped out), but I’m struggling with trying to figure out how to display my attachMovie’d items in a logical row/column fashion… i.e. if I had 7 items in my XML file and wanted the row to exist in threes, I’d have two rows of three and one row of one.

I’m sure there’s a very simple solution to this that I’m simply overlooking. I was just thinking about trying to implement this via some type of counter/multiplier for the _y property. Perhaps after lunch I’ll give that more thought, but if someone has advice in the meanwhile, I’d appreciate it very much.