Escaping the $1 parameter in stored procedures - Mailing list pgsql-sql

I'm running Postgres 7.3.2 in Redhat 9.0.

I'm trying to execute a function below defined as a stored procedure
  ALTER TABLE tms_schedule DROP CONSTRAINT "$1";

However, postgres thinks the "$1" is a parameter value.  How do I tell
postgres to treat it as a literal $1?

TIA,
Robert