Using Flex Builder :  

I have created a new Actionscript Project.
I want to use mx.controls.Button class in it,
so I did the following : 

1. Added '-locale=en\_US -source-path=locale/{locale}' to the Actionscript compiler arguments
2. Added 'framework.swc' to the library path

But now I get this error:
**unable to open 'locale/en\_US'**
I looked up and I do have the following directory inside my Flex Builder 3 installation: 

./sdks/3.0.0/frameworks/locale/en\_US

How to fix it?