请问以下过程有哪些错误！！！100分。

请问以下过程有哪些错误？

CREATE OR REPLACE PROCEDURE "SYSTEM"."UPDATE_SUBJECTTYPE"
as
cursor signcursor is
select * from system.A;
errormessage exception;
accountrecord system.A%rowtype;
acccountsign varchar2(10);
s number;
accountnumber varchar2(50);

begin
open signcursor;
if signcursor%notfound then
raise errormessage;
end if;
loop
fetch signcursor into accountrecord;
accountnumber :=accountrecord.ACCOUNT_NUMBER;
s := select count(*) from system.A where A.ACCOUNT_NUMBER like accountnumber and ACCOUNT_NUMBER!=accountrecord.ACCOUNT_NUMBER;/*提示有误！*/
if ( s = 0) then
acccountsign:='leaf';
else
acccountsign:='notleaf';
end if;
exit when signcursor%notfound;
update system.A set sign = acccountsign where ACCOUNT_NUMBER =accountrecord.ACCOUNT_NUMBER ;
end loop;
close signcursor;
commit;
end;