MAX30 / TopAndDownButtonsEverywhere

Hi! Nice work!

But can you make an other button to stop all scroll. It's because when you scroll down it's for all the document height and you can't stop or invert that.
I've try something, create a new button, change values, create var, but i don't know so much .js so that don't work ^^'
_ PS: sorry for my english, I'm french!_