is this possible in plpgsql ?

I have 1 function in pg 7.3.2.

txt string have 1,2,3,.. and i would like to be similar like if 3 in
(1,2,3..) then, but IF 3 in (''''||txt||'''') THEN doesn't work.
There is possible to this or not ?

CREATE OR REPLACE FUNCTION rek2(INT8) RETURNS text AS '
DECLARE       i                       INT8;
BEGIN       txt := '''';       for i in 1 .. 10 loop               txt := txt||i||'','';       END loop;       txt :=
txt||''0'';      IF 3 in (''''||txt||'''') THEN               raise notice ''yep'';       END IF;       RETURN txt; 
END;
' LANGUAGE 'plpgsql';

--
"Nieobecni nie mają racji"

Marcin Winkler