How to change default isolation adn wait mode

Our databases have committed read isolation and lock mode to not wait. Is there any means of changing this ?? I certainly am aware of isolation/lock modes in my ESQL/C programs and I know you can do passthrough SQL in VB ( most client apps implented in this) to set iso/lock modes. However, maintaining discipline is not always there. Also, there are reporting programs (Business Objects) and other "technologies" that attach to the database that really IMHO should have at least dirty read isolation. Thanks, -Lin