Hide sticky add to cart when reaching footer

Hello,

1. I have enabled the sticky add to cart on single product pages. Is there a script that I could use to hide it when user reaches the footer in a sumilar way that it hides itself when it reaches the top of the page?

2. On the side cart is there any way to have two buttons at the same time? One for the cart page and one for the checkout?

Thank you for your nice work.

Barnabas