Probs "compiling" a function

Greetings, Having probs just "compiling" this fn and it comes back with a very
stark error msg which is below. I'm using version 7.1.3

I run the script as:
\i procedures/zff

and get the error msg:
psql:procedures/zff:51: ERROR: parser: parse error at or near "b"

Line 51 is the line that starts LANGUAGE....

And the script is:
CREATE FUNCTION bsub_insert(varchar,varchar,varchar,varchar,varchar,
varchar,varchar,varchar,varchar,varchar,bool,date,int2,int4,varchar,int4)
RETURNS integer AS '
DECLARE
tmp_bsub RECORD;
t_sub_id2 INTEGER;
t_class_sun INTEGER;
p_band_nm ALIAS FOR $1;
BEGIN
IF p_band_nm IS NULL THEN
RETURN 0;
END IF;
IF $3 IS NULL THEN
RETURN 0;
END IF;
IF $4 IS NULL THEN
RETURN 0;
END IF;
IF $11 IS NULL THEN
RETURN 0;
END IF;
IF $12 IS NULL THEN
RETURN 0;
END IF;
IF $15 IS NULL THEN
RETURN 0;
END IF;

SELECT INTO tmp_bsub *
FROM sub_class
WHERE sub_class.class_ds = upper($15);
IF NOT FOUND THEN
RETURN -1;
END IF;
t_class_sun := tmp_bsub.class_sun;

INSERT INTO sub(band_commnty_nm,street_no,first_nm,surname,home_phone_no,
work_phone_no,mobile_phone_no,email_tx,web_addr_tx,sub_comment,
voluntr_fl,sub_expiry_dt,card_cnt,receipt_no,sub_type_ind,
class_sun,street_sun)
VALUES(upper($1),$2,upper($3),upper($4),$5,$6,$7,$8,$9,upper($10),$11,
$12,$13,$14,/'B/',t_class_sun,$16);

GET DIAGNOSTICS t_sub_id2 = RESULT_OID;
SELECT INTO tmp_bsub *
FROM sub
WHERE oid = t_sub_id2;

RETURN tmp_bsub.sub_no;
END; '
LANGUAGE 'plpgsql';

Thanks for any help as this is driving me made and I've rewritten it checked all
the b's and compared it to other fns I've written and nothing I'm using here I
haven't already used.

Cheers...Gordon