If the email containing your password did not arrive, it may have been eaten by a spam filter. If you are able to, browse your "spam" folder, the password message may be sitting there. If you can't do that, try temporarily turning off your spam filtering, and requesting a new password.
To request a new password, pls visit http://www.netbeans.org/servlets/PasswordRequest. Enter your username (or email address), and click "New Password". You may need to disable your spam filter before trying this, as the password mail may be falsely detected as spam.