[Zope] How To Access Superuser?

Hi, I'm a total newbies. I installed Zope 2.0.3 and Zope zserver on RH7. I couldnt access the superuser directory. I used the default username and password but didnt work out. Then I changed the password zpasswd and chose cleartext. However, that still didnt work out. Please help. -suhardi-