Simple script for adding users

Hi guys,

I've a simple linux script (made by my friend), which adds users to the system from userlist file. it also creates user home dir and copies certain files to the directory. To be honest, am a newbie in scripting so am unable to fully understand how the script is working. unfortunately, my friend is out of town so i cant get any help from him as of now. Thats why i posted it here. I hope someone from this forum could help me out on it. Code link :

http://pastebin.com/pSaYanBP

Thanks