Add dynamically values to a combo list in Oracle D2k Forms

-- first  method using creategroupfromquery function creating a recordgroup dynamically
declare
myrec RECORDGROUP;
begin
if not id_null(myrec) then
   delete_group(myrec);
end if;
  myrec := CREATEGROUPFROMQUERY('otmp','select  decode(emp_grade,'S','Staff', 'W', 'Worker','') ,emp_grade from employee_master');

if poplatre_group(myrec) =0 then
    clear_list('control.combolist1');
    populate_list('control.combolist1',myrec);   
end if; 
end;

--second method, using a explicit cursor and add to list using add_list_element

declare
cursor rec is  select  decode(emp_grade,'S','Staff', 'W', 'Worker','') emp_grade_desc ,emp_grade from employee_master;
reccount  number:=0;
clear_list('control.combolist1');
begin
 for o in rec loop
   add_list_element('control.combolist1',reccount,o.emp_grade_desc,o.emp_grade);
   reccount :=reccount +1;
 end loop;
end;