Track inventory feature with dynamic created "add to cart button"?

i have actually u开发者_开发问答se form code to auto-generate information and etc.

I was wondering if i can implement the "track inventory qunatity" using dynamic generated buttons , just like in the website?

If this is not possible, how do i actually counter check with my own item quantity everytime a user press "add to cart" and it will minus off 1 quantity from my database.

And when they cancel the checkout , i would get the "-ed 1" back to my database?

Thanks alot, this is my first time working with paypal and have totally no clue

you would most likely handle that in your database with a stored procedure