create or replace function AUTO_YEAR_SEQ_FUNC
return varchar2
is
l_ret_val VARCHAR2(100);
l_existing_max_year NUMBER;
l_current_year NUMBER;
l_val VARCHAR2(100);
l_col_size NUMBER;
begin
select data_length-5
into l_col_size
from user_tab_columns where table_name='TEMP_SEQUENCE'
and  column_name='SEQ_VAL';

  select max(to_number(substr(seq_val,-4)))
  into l_existing_max_year
  from temp_sequence;

  select to_number(to_char(sysdate,'YYYY'))
  into l_current_year
  from dual;

  if l_existing_max_year=l_current_year then
    select lpad((max(to_number(substr(seq_val,0,instr(seq_val,'/',1)-1)))+1),l_col_size,'0')
    into l_val
    from temp_sequence
    where substr(seq_val,-4)=to_char(l_current_year);
  else
    select lpad((max(to_number(substr(seq_val,0,instr(seq_val,'/',1)-1)))+1),l_col_size,'0')
    into l_val
    from temp_sequence
    where substr(seq_val,-4)=to_char(l_current_year);
  end if;
    if l_val is null then
    select lpad(1,l_col_size,'0')
    into l_val
    from dual;
    end if;
  l_ret_val:=l_val||'/'||l_current_year;
  return l_ret_val;
end;