my Ipod nano doesn't show up in itunes and in finder just like an extern unit. What has happened??

Just like above. The history is

An old ipod (4, 5th generation)

A few months ago my friend tried to sync it to her windows computer and had to erase all music (it's been compatible to mac always before) but then she could't put in any new music either.

Then it's just been laying around uncharged.

Now I try to sync it to my new macbook pro (itunes 1.11) but it doesnt show up in itunes. When i plug it in itunes show up over all the other programs but i cant find the ipod in it. In finder it's just a device with "NO NAME"

i don't know how to fix this, please help me!