How do I scroll down? ^_^

Hey there! ^_^

What i was wondering about was the scrolling down system -

If we take a look at like for example, any classic RPG game, such as Final fantasy 7 or Breath of fire 3 -

When you recieve items to the inventory, you can scroll down.

I got the inventory part here, but how can one do the scrolling down?

Thanks in advance.