Hi there, new here and have question

Hi Everyone.
I'm just subscribe to the mailing list
I'm new to Postgresql and
I have a question

I intend to make a function that returns more than a row
I tried something like below

create function listofemployeebasedondepartment(id_dept int) $$
declare
 resultset ??;
begin
    select * into resultset from employee where id_dept = id_dept;
    return resultset;
end
$$ language 'plpgsql';

I believe you get what I want
But I just couldn't finish the code since I miss something
I manage to find 'setof' but have no idea on how to use it

Any suggestion everyone?

Thank you,
Regards,
Hendra