Adding a user: username

[cnw]

I'm adding a user to a club account.  The form that asks for the information about the user just tells me to choose a username and password.   When this user tries out the username and password that I chose the system asks him for  an email address.    Should I get an email from this user and use that as his username?  If the username is supposed to be an email why doesn't the form indicate that?

[sharpiemarker]

Get an email address from the user and make that the username.  No idea but generally PayPal uses email address as the username.

[cnw]

The problem is that the instructions for adding user, next to username shows:  8-16 English alphabets characters, no special characters, must be unique

So that makes it pretty hard to use an @ sign.