DB to DB Trigger

[Dan Hooley]

I'm trying to set up a trigger to update a table in another database with the value from the table in this database. Here's my code so far, but doesn't work:

BEGIN
if new.ListID <> old.ListID then
update bebmain.a_entities_qblink set ListID = new.ListID where ListID = old.ListID;
end if;
END

What I want is if the ListID column changes, I want the ListID in the table in the other database to reflect the change, if there is a matching record in that table.