Hi I'm getting the following error:

Access restriction: The type MainFrame is not accessible due to restriction on required library /System/Library/Java/Extensions/j3dutils.jar

when im trying to import following:

import com.sun.j3d.utils.applet.MainFrame;
import com.sun.j3d.utils.geometry.ColorCube;

How do I lift off this restriction or what should I do?

I'm using eclipse on Mac OSX Lion

Thanks in advance.