function check_privileges(par_emp_id in number, par_app_id in number)
  return boolean
is
  l_var number;
begin
  select null
    into l_var
    from your_table
    where emp_id = par_emp_id
      and app_id = par_app_id;

  return (true);
exception
  when no_data_found then
    return (false);
end;

-- :THIS_EMP_ID represents current employee
-- 2 is a form whose APP_ID = 2

if check_privileges(:this_emp_id, 2) then
   call_form('form_2');
else
   message('You are not allowed to run this form');
   raise form_trigger_failure;
end if;