Forms :: Update Table With Cursor

I have made changes in my form

1st step:-

for Inserting records created below cursor, records are inserted and I can see on my screen (form) also.

DECLARE
CURSOR InvestIS
select * from Tempinvest;
BEGIN
OPEN Invest;
GO_BLOCK('ReturnReport');
last_record;
[code]......

2nd step:-

Updating records
I wan to update some columns in this table so I created a 2nd cursor to update records but this cursor is not working accordingly. my requirement is: before Update first of all Find inv_co_code & inv_fnd_code when find then update column Redunits

2nd Cursor

DECLARE
ddate date; refdate date; co_code number; co_name varchar2(50); fnd_code number; fnd_name varchar2(50); units number; amount number; stat varchar2(1);
CURSOR bnr IS

select Ddate,refdate,co_code,co_name,fnd_code,fnd_name,units,amount,stat from (
select inv_date DDate,Vdate RefDate,inv_co_code Co_code,inv_co_name Co_name,inv_fnd_code Fnd_code,inv_fnd_name Fnd_name,
inv_nofu Units,inv_amount Amount,Status Stat from (
------------- Bonus -------------------
select inv_date,vdate,inv_co_code,inv_co_name,inv_fnd_code,inv_fnd_name,inv_nofu,Inv_amount,inv_uprice,'B' Status from investment
where code is null and inv_date <= :dd1
---------------- Redemption --------------
Union All
select red_date,null,red_co_code,red_co_name,red_fnd_code,red_fnd_name,red_nofu,red_amount,red_uprice,'R' Status from redemption
where red_date <= :dd1
))
where co_code = 13 and fnd_code = 1
order by co_code,fnd_code,ddate ;
------------------------------------------
vddateddate%type;
vrefdate refdate%type;
vco_codeco_code%type;
vco_nameco_name%type;
[code].......