How to create a setup project that supports multiple instances (multiple installing)?

I'm using Visual Studio 2010, and I have created a project which I'm trying to install us开发者_StackOverflow中文版ing the setup from Visual Studio 2010. How do I installed it multiple times?

I didn't find the answer on the web. I have read some documents about orca and transform but not an understandable example.

---

In project property you will see a property called UPGRADECODE Generate a new code and proceed with build and you can now able to install multiple time of same version.