Can you help me with this japanese?

Anywho, I'm registering for Nico Nico Douga, and I apparently did it wrong. I'm trying to send in my form, like, my nickname, and stuff, but I'm confused. Japanese letters pop up and I think I'm doing it wrong. It has a 8~16 thing at the top. I made my nickname "milly123" "millerz14" "cryinglaughterftw" "cryinglaughter14" but nothing has been working. Is there any possible way for someone to check it for me...? I'm so confused, but really want an account.