i can't add ringtones into itunes 12

hi, i just bought a new computer got my itunes 12 downloaded, than took me 2 days to download all my music, apps, movies, ect from itunes store back to my computer. than i had made some ringtones as .m4r files, but i can't drag them into itunes!!!!!! after i draged them into itunes, it appeared in the music lib, but not the ringtone lib, and i can't add them anyway doesn't matter if i change the file into .m4r or .m4a or .mp3, they all appeared in the music lib, and even if i sync my iphone with it, it will appear in my music but i can't see any of them in the settings=>sound=>ringtone.

even i deleted all the ringtone in itunes which was only one that was brounght on my phone (didn't know how it get there, i got other ringtones i purchased in my iphone, but they didn't got into itunes)

so here are two main questions:

1: how to add customised ringtone into itunes 12

2: how to add ringtones purchased from iphone into itunes 12