inserting arrays from plpgsql.

Dear all,

i am trying to insert an array from a plpgsql function. But it didnt
work and i didnt know where i am wrong. hope to get some lights.

my need is something like this..

create table po
(
comp_code text,
po_no text,
po_details text[]
);

create table xx
(
comp_code text,
po_no text,
po_line1 text,
po_line2 text
);

and my function is..

create function ftest()
returns opaque as 'declare

array_params po.po_details%type;

begin
array_params := {new.po_line1, new.po_line2};
insert into po values
(comp_code, po_no, params)
values
(new.comp_code, new.po_no, array_params);

return new;
end;'
language 'plpgsql';

create trigger ttest after insert on xx for each row execute
procedure ftest();

----

my need is not exactly the same, but very similar.
Will be very happy, if I get some lights!

Regards,
Bhuvaneswaran.