Error in upgrading 9.2.0.1 database to 10g

Today, I was trying to upgrade my 9.2.0.1 database to 10g. I installed the 10g server, and run the Pre-Upgrade Information Tool (utlu102i.sql) to analyze and prepare my 9.2.0.1 database for upgrade.

SQL> @?/rdbms/admin/utlu102i
DECLARE
*
ERROR at line 1:
ORA-20000: Version 9.2.0.1.0 not supported for upgrade to release 10.2.0
ORA-06512: at line 1523

It turned out that I should have upgraded it to at least 9.2.0.4 before installing 10g server software. Should have....
Here is the link to the upgrade documentation.