filter highlighting (different class for even / odd rows)

I've used the plug in shown at the bottom of

http://datatables.net/forums/discussion/2123/filter-post-processing-and-highlighting/p1

Works great, thanks to the people that did the hard yards on this.

I'd like to enhance it so that the css class applied is different for even or odd rows (background color of rows mandates a different highlighting method).

How can I determine whether the nRow being operated on is an even or odd row on the currently displayed table?