Pass parameters to a TCL function

Hello list,

I have a tcl trigger function called audit_log(varchar, bpchar), if I
write a trigger in a table

CREATE TRIGGER tg_test
   AFTER INSERT OR UPDATE OR DELETE
   ON xtable
   FOR EACH ROW
   EXECUTE PROCEDURE audit_log('xtable','internal');

it gives this error:

ERROR:  CreateTrigger: function audit_log() does not exist

I also tried to make a kinda wrapper plpgsql trigger to call the
audit_log function but didn't work, any idea what's wrong?, how do I
pass parameters to a trigger function?

Thanks in advance,

Josue Maldonado.