How to create a table for auditing?

[tamilselvan]

create or replace trigger audittrigger
after insert or delete or update on demo1
for each row
begin
if inserting
insert into audittable values('INSERT', user, sysdate);
elsif updating
insert into audittable values('UPDATE', user, sysdate);
elsif
insert into audittable values('DELETE', user, sysdate);
end if;
end;
/