n tier development

Question

if you are developing a 4 tier database application where the 4th tier is the database server (MS SQL), where do you construct the connection string. Given that the database is to be distributed you must allow the flexibility for your users to provide the name of the server and possibly the name of the database. My approach in the past would have been to store the server and database on the client in the registry. Strictly speaking the client should not have to worry about the server or database name. what is the correct solution ?