Dial fell off my camera?

The Nikon D80 that I have, the dial thing on the top left that says what mode your shooting in, fell off last night.

Well… The top part with the pictures on it, so now i have no idea what i'm shooting in… And i don't know how to put it back on in the correct spot.

It isn't my camera, its a lone from my school… I wondering if i can fix this with some help from you guys.

A or S will be visible in the top LCD. The plate itself is just a matter of a bit of superglue