adding nyc tax as well as ny state tax

Hi,
The site I am working on will have to add new york city tax as well as ny state tax to their purchase. I know the cart is set up to add state tax, I have used it before. How do I go about adding the city tax and how will my confirm form know this?
Thank you,
KK

the city they enter is stored in a session variable called 'eCartCheckoutForm_shipping_city'




create a new city tax and set the trigger to Session Variable exists "eCartCheckoutForm_shipping_city"

AND
based on session variable value:
if the session variable "eCartCheckoutForm_shipping_city" has a value equal to "NY NY"

OR
based on session variable value:
if the session variable "eCartCheckoutForm_shipping_city" has a value equal to "Queens"




and continue adding OR statements for all of the NY Cites the tax should apply to.