Backpack question

[CJ]

So I just started the game and met one of my first people who gave me a key to open a door in a house. It is my understanding that the key was placed in my backpack. I found the door to open that requires the key but I cant seem to switch between the different parts of my backpack to get it.. how do I do this? is there a way to scroll... or can you not do this?

[Trollface]

3 page slots for loot + 1 page slot for quest item. just click > several times