Before Insert Trigger question

[Scott Selvia]

I'm trying to assign values automatically to a row prior to the row
being inserted.  I have no problem doing this with MySQL or Oracle,
etc...

However in Derby I was trying issued the following statement and the
last_update_uid is populated with the content of the value in the
insert statement.  How can this be done in Derby?

create trigger clients_trigger
  no cascade before insert on clients
  referencing new as newrow
  for each row mode db2sql
  values (newrow.last_update_uid = CURRENT_USER, newrow.last_update_ts
= CURRENT_TIMESTAMP);

Thanks,

Scott