Please help itunes music all gone??

All my music on my itunes libary is gone but all d songs r still on my ipod! when i put my ipod on d computer it tells that my ipod is synced wit another itunes libary and says dat i have 2 delete all my music so i can sync my normal libary but i avnt put my ipod on ne other libary plz tell me wat i can do??? sorry email not working r u able 2 write it out on dis?
Answer
First of all, copy all tunes, vids, and movies you have on ipod to one folder onto your pc. then just a case of downloading and re-installing new ipod settings from itunes and copying over files you saved, re-installing will clear any corrupted files, which sounds like you have.