How do I put line space between the products on the main page product listing?

class="productListing-odd"
class="productListing-even"

I know I need to adjust something in the above parameters. But I can not find out how/where.

I would like more "white" space between the products listed on this page:
http://westdakotakobe.com/shop/index...index&cPath=65

The space is NEEDED because the BUY NOW button and PRICE for each product sort of RUN into each other - it would look much better if there were extra space above/below.

Thanks for looking and helping.
Luci