Parameters if trigger...

Hi all!

May I use function with parameters with triggers?
When I try it I have error: "Can't find function ......".
Is it normal?

Postre can't find my function..... Why?

create function mytest(text) returns opaque as '
declare
parma1 like as $1;
begin
return NEW;
end;
' language 'pgsql';

Best regards,
Mik.