sequence trigger

I want to use a sequence in my table, and Id like it done in a database trigger.
I performed the following steps:
1) create sequence myseq;
2) create table mytable
(pk number(13),
name varchar2(30));
3) create or replace trigger mytrig
before insert on mytable
for each row
begin
update mytable
set new.pk=myseq.nextval;
commit;
end;

when I attempted an insert, insert into mytable (name) values ('mark'); I got the following:

SQL> insert into mytable (name) values ('mark'); insert into mytable (name) values ('mark')

            *
ERROR at line 1:

ORA-00904: invalid column name
ORA-06512: at line 2
ORA-04088: error during execution of trigger 'MARK.MYTRIG'

Appreciate any help!
Thanks, Mark
auritma_at_mail.northgrum.com Received on Wed Jul 16 1997 - 00:00:00 CDT