update column with rowtype

Hi..

I try "rowtype" in trigger, ex:
create or replace function fn_tr_aiu_pdcblc() returns trigger as '
declare
c_pdcblc cursor for select * from t_pdcblc where fc_branch=new.fc_branch
and fc_bankacct=new.fc_bankacct;
balance decimal(30,5);
row_pdcblc t_pdcblc%rowtype;
begin
balance:=0;
if (select count(*) from t_pdcblc where fc_branch=new.fc_branch and
fc_bankacct=new.fc_bankacct and fd_trxdate<new.fd_trxdate)>0 then
balance:=new.fm_balance from t_pdcblc where fc_branch=new.fc_branch
and fc_bankacct=new.fc_bankacct and fd_trxdate<new.fd_trxdate;
end if;
open c_pdcblc;
for c_pdc in 1..(select count(*) from t_pdcblc where
fc_branch=new.fc_branch and fc_bankacct=new.fc_bankacct and
fd_trxdate>=new.fd_trxdate) loop
fetch c_pdcblc into row_pdcblc;
row_pdcblc.fm_balance :=
balance+row_pdcblc.fm_masuk-row_pdcblc.fm_keluar;
raise notice ''balance %'',row_pdcblc.fm_balance;
new.fm_balance := row_pdcblc.fm_balance;
end loop;
close c_pdcblc;
return new;
end;' language 'plpgsql';

the result of this trigger is;
oid | fd_trxdate | fm_masuk | fm_keluar |
fm_balance
--------+--------------------- +------------ +-----------+------------
562784 | 2003-02-06 00:00:00 | 1000.00000 | 0.00000 | 0.00000

and which command i could used to fill column fm_balance with 1000?
please gimme some idea...???

thank's
betty

thank's