plpgsql notify trigger

[postgres 7.0.2, x86 linux]

I am trying to use a trigger to perform an sql 'notify' command.
I do something like:

CREATE FUNCTION run_changed() RETURNS opaque AS '
declare
nm text;
begin
nm := NEW.run_name;
notify nm
return null;
end;
' LANGUAGE 'plpgsql';

create trigger run_changed_tr after update on runs for each row
execute procedure run_changed();

BUT, when I update the table, I get:
ERROR: parser: parse error at or near "$1"

It looks like the *name* (or it's alias here: $1.run_name), not the *value* of the variable nm,
is passwd to the notify command. Since notify only takes a name, not a string,
I don't see how to proceed.

Is there some way in plsql to construct a string and have it executed in sql?

disappointed in plsql,
George

--
George Young, Rm. L-204 gry(at)ll(dot)mit(dot)edu
MIT Lincoln Laboratory
244 Wood St.
Lexington, Massachusetts 02420-9108 (781) 981-2756