function with multiple return values

I've created the following function:

CREATE OR REPLACE FUNCTION latest ( lot_id int4,
  condition text, OUT perc smallint, OUT entry_date date )
RETURNS SETOF record AS
'
BEGIN
        RETURN QUERY SELECT  t1.perc, t1.entry_date
         FROM    t1, t2
         WHERE   t1.condition_id=t2.id and t1.lot_id = $1 and t2.code = $2
     ORDER BY entry_date DESC LIMIT 1;
END;
' language 'plpgsql' VOLATILE;

It works for this:
select (latest(38787,'IP')).*
    returning perc and entry_date each in it's own column.

Problem is:
select (latest(38787,'IP')).*, (latest(38787,'FI')).*;
   returns 4 columns:   perc, entry_date, perc, entry_date

Tried:
select perc as p1, perc as perc2 from (
   select (latest(38787,'IP')).*, (latest(38787,'FI')).*
) as foo;
just to see -- it says perc is ambiguous...  well yes it is!  :)

Ideas on how to uniquely name the first and second set of "perc,
entry_date"?
Or maybe there is a different way to return 2 values from a function?

Thanks,
Scott