Flash :: Namespace Error: "Top Level Of A Class Definition"?

I'm trying to encapsulate a package so that classes, properties, and methods that have no meaning outside of the project aren't accessible. They do, however, have to be accessible by other classes in the project, so internal is insufficient - the internal properties of parent.foo.AClass can't be accessed byparent.bar.AnotherClass. I was under the impression that namespaces could solve this problem, so I tried this:

//Class in top level package, where we make our namespaces
package parent {
public namespace myproject;

[code].....