Swap database instance at runtime

Hi All,

I have one WO application which i would like to connect to different  
databases (1 db for each customer). The database schema is the same  
for all of them. My question is: how can i  (if  possible) @ runtime,  
swap the EO model/objects to connect to a different database instance?

A small peace of example code would be appreciated.

Many thanks in advance,

Roger