oracale and array

hi,
i put this in the development forum..but no repy for 1 hr:(
so i thought i would ask where the real gurus xists:)

can i bind an array?
if yes how?
DECLARE
TYPE p_tab IS TABLE OF varchar2(200) index by binary_integer;
lAnswer p_tab;
i number:=0;
a2 varchar2(30):='#';
BEGIN
FOR x IN (SELECT distinct id FROM TEST_SAM group by id) LOOP
lAnswer(i):='#';
FOR y IN (SELECT name FROM TEST_SAM where id=x.id) LOOP
if a2 ='#' then
a2 := x.id||','||y.name;
else
a2 := a2||','||y.name;
end if;
end loop;
:lAnswer(i):=a2;
i:=i+1;
a2:='#';
END LOOP;
END;

i tried this but it give me error:

ORA-06550: line 16, column 1: PLS-00308: this construct is not allowed as the origin of an assignment

help plss...thank you