How can I specify Java 1.6 sourcepath in IDEA 7.0.4 on Mac

I downloaded the Java 1.6 source (src.jar) from the Apple Developer Connection and installed it in /System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Home. I went to add it to my IntelliJ sourcepath so I could refer to the Java source, but when I use the "Add..." button and navigate to the /System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Home/src.jar/src directory and try to select it, I get the following error message: "Specified path cannot be found." If I select src.jar itself, that error does not appear, but command-clicking java classes brings me to compiled classes, and not the Java source. How do I specify the sourcepath for Java 1.6 on a Mac?

Check out the attached screenshot to see what I'm trying to do.

Thanks!