[DotNetDevelopment] how best to structure the visual studio to work with multiple environments (eg development, approval and production)

[Molleri F´]

I'm starting to develop a project that will share in both desktop and
web use in 3 environments:
development, approval and production. What would be the best way to
structure this project in visual studio to work?
how I can organize the different connection strings for each scene in
time to make the deployment of the application?
I can do this with the same solution, or I need three versions of a
solution for each environment?
I will use this project with the svn for version control.
now thanks.