plpgsql and arrays

I'm trying to write function which accept array and insert each element
in table:

=# SELECT * FROM add_user('{user1(at)domain, user2(at)domain}');
ERROR: column "email" is of type character varying but expression is
of type record
HINT: You will need to rewrite or cast the expression.

table is with values (uid, email):
uid - smallint - not null default nextval('users2_uid_seq'::regclass)
email - character varying(128) -

function is like this:

CREATE OR REPLACE FUNCTION add_user( VARCHAR(128)[] ) RETURNS SMALLINT AS $$
DECLARE
v_rec RECORD;
v_uid SMALLINT;
v_email VARCHAR(128);
empty BOOLEAN := TRUE;
BEGIN
FOR v_rec IN SELECT $1[i] FROM generate_series(array_lower($1,1),
array_upper($1,1)) s(i)
LOOP
IF ( empty = TRUE ) THEN
INSERT INTO users2 VALUES (DEFAULT, v_rec);
empty = FALSE;
SELECT INTO v_uid currval('users2_uid_seq');
ELSE
INSERT INTO users2 VALUES ((SELECT currval('users2_uid_seq')),
v_rec);
END IF;
END LOOP;

RETURN v_uid;

END;
$$ LANGUAGE 'plpgsql';

I'm trying to cast it to varchar, but it doesn't help.