INOUT text[],OUT text parameter handling problem

CREATE OR REPLACE FUNCTION fbind(

    IN p_parm_value_i text,

    IN p_psudo_datatype_i character varying,

    OUT p_result_string_o text,

    INOUT p_bind_values_io text[])

  RETURNS record AS

$BODY$

BEGIN

p_bind_values_io := array_append(p_bind_values_io, p_parm_value_i);

CASE p_psudo_datatype_i

   WHEN 'cvs num' THEN

      p_result_string_o := '= ANY ((''{''||$'||array_length(p_bind_values_io,1)::text||'||''}'')::bigint[] ) ';

   WHEN 'bigint' THEN

      p_result_string_o := '= TO_NUMBER($'||array_length(p_bind_values_io,1)::text||',''99999999999999999999'') ';

   ELSE

      p_result_string_o := 'datatype not implemented';

END CASE;

RETURN;

END;$BODY$

  LANGUAGE plpgsql;

DO $$

DECLARE 

  using_values text[] ;

  p_result_string_o text;

BEGIN

   using_values := array_append(using_values, 'the first entry'::text);

   p_result_string_o := fbind('1234'::text, 'bigint'::character varying, using_values);

   raise notice 'p_result_string_o:%', p_result_string_o;

   raise notice 'using_values:%', using_values;

END$$;

 NOTICE:  p_result_string_o:("= TO_NUMBER($2,'99999999999999999999') ","{""the first entry"",1234}")
NOTICE:  using_values:{"the first entry"}