Calling triggers with arguments

Greetings,

 I've come across something that either doesn't work spec'd or I'm
missing something (I suspect the latter). I'm trying this:


  CREATE TRIGGER classified_index_trigger
  BEFORE INSERT OR UPDATE ON ads
  FOR EACH ROW
  EXECUTE PROCEDURE htdig_index('classified_en');

and the error message I get is:

  ERROR:  function htdig_index() does not exist

However if I do \df htdig_index I get this:

                       List of functions
 Result data type | Schema |    Name     | Argument data types
------------------+--------+-------------+---------------------
 "trigger"          | public | htdig_index | text


Is there something I'm missing in order to pass an argument in a
trigger?  I've tried double quotes, and two singles as well as no
quotes, and all lead to the same thing.

 Any info would be much appreciated.

Cheers,

Chris

--
Christopher Murtagh
Enterprise Systems Administrator
ISR / Web Communications Group
McGill University
Montreal, Quebec
Canada

Tel.: (514) 398-3122
Fax:  (514) 398-2017