Thanks. I think yum will be very useful.
However, I'm faced with some difficulties.
1)I have write to hard disk all the rpms from the FC4 cd. The directory containing the rpms is /root/RPM.
So now, I want to create a respository using yum-arch /root/RPM
But I get many error messages that say "rpmError opening rpm packagename - error public key not available"
2) when I try to yum install packagename, I get this error message "Cannot find a valid baseurl for repo: updates-released"