disable cached userid & password?

How can I disable the userid and password cache on the Netscape 4.7 browser when the firewall asks for it as a part of Internet authentication process.

According to the Netscape 4.7 support article, the userids and passwords are never saved to disk. However, they are stored in an encrypted temp file for the length of the current session. There is no way to empty the record of that password except by restarting the browser.

I would apprecite if some on out there could
help on this issue!

Thanks in advace !