Variations question

So I am able to create a variation for my product page which looks like this – http://fragranceoilwarehouse.com/?product=1-million-type-mens-13

I made the drop down menu but I need to learn how to set the product options(sizes drop down) to change prices when someone were to click on the option they want, I was the price and option to change.

Does anyone have any insight?

http://wordpress.org/extend/plugins/woocommerce/