Help / My PC was infected by viruses, lost everything

, but have backups of photos on external harddisk and my music is on my iPhone. My PC is now clean, I have reinstalled iTunes but it will not put my music from the iphone to the PC. It says that my iPhone is sync'ed with another iTunes library and only gives me the option to sync with new library which is empty...How do I save my music?
Thanks a lot for any help and advice you may have