Require Username to be E-mail

[tylast]

How would I require the username to be the registered e-mail address? The reason I want to do this is because I'm running this board on an internal site & everyone's e-mail addresses are already incorporated into the user's entire name.

Is there a way (druring registration) to have the username field popluated with the e-mail address automatically and not editable by the user?

[Logician]

edit register.php, find:

$username = trim($username);

replace it as:
$username = trim($email);

Note username will be different than email IF user changes his email later in his user cp.