URI Routing from CI app name to my web root

[eluser]tlam[/eluser]
Right now, I can access pages within the framework like the following:

http://localhost/codeigniter/helloworld

I already have existing modules under localhost and would like to slowly migrate my old codes to CI. For the time being, I'll code my new modules in CI. What should I change to display my CI modules under localhost(assuming that they are unique), for example:

http://localhost/helloworld