cards balance

.create or replace procedure balance as
acno number:=&acno;
txnno varchar2(20);
bdate date:=&bdate;
cou number;
cdno varchar(16);
cid number;
bal number;
begin
select count(*) into cou from customer_master where accno=acno;
select cin,balance into cid,bal from customer_master where accno=acno;
select cardno into cdno from card_master where cin=cid;
if(cou>0) then
select to_char(bdate,'ddmmyyyyhhmiss')||transeq.nextval into txnno from dual;
insert into daily_transactions values(cdno,bdate,bal,0,0,txnno);
commit;
dbms_output.put_line('Your Account Balance is '||bal);
else
dbms_output.put_line('Account Number Does Not Exist');
end if;
end;
/