NLS Character set changing

Hi,

I am trying to change my oralce8i 8.1.7 installation on W2000 server character set from 'WE8ISO8859P1' to 'UTF8' when I am running 'alter database character set UTF8;' I am getting following error

alter database character set UTF8
*
ERROR at line 1:
ORA-12712: new character set must be a superset of old character set.

But I need to change to UTF8. How can I do this?

Could someone help me please

Raj

Want to do it officialy supported way, so your Oracle support contract remain walid? Then the only way is to do full export of your old database, create a brand new database with new character set and then import previously exported data.