plpgsql question

I'm trying to do a simple SELECT * in plpgsql that returns a set of records as a row w/ columns, not a row into a variable, w/ some conditionals.

The function below is semi-pseudo with what I'm trying to... If anyone could give me an example that works by returning it as a resultset maintaining the columns, that would be awesome and I could take it from there.

I've read the pl/pgsql section of the docs and the Douglas book but I'm still confused on this issue...

Thanks

create or replace function getrecord(int,text) RETURNS SETOF records as $$
DECLARE
-- event := rows to return from the table below

BEGIN
event := SELECT * FROM my_tbl
WHERE 1 = 1
and my_tbl_id IN (0$1) ||
' IF $2 IS NOT NULL THEN' || and username = $2 || 'END IF;'
; -- end sql statement

RETURN event;

END;
$$ LANGUAGE plpgsql;