Use Email Address As Username

Hi

Im still quite new to Hikashop and maybe there is a simple answer to my question but

I would like shoppers to use their email address as their username. How can I make the existing email field in the registration form also useable for the username?

Thanks

Tony

I followed your instruction here to reach what i wanted to do and it works.
Now how can i change the text "Nome utente (username)" with text e-mail?

Thanks
FRank