Call function in parent class from child class

1

Right, so I have a main Document class called Bundl where I’m loading all my other classes (navigation, portfolio, …). What I’m trying to accomplish is to call a function inside my main Bundl class from a click from the navigation class.

The situation in code:
The Bundl Class (located in the root folder)

package {
	import be.bundl.Navigation;

	public class Bundl extends Sprite {
		//vars called here

		public function Bundl() {
			nav=new Navigation("xml/navigation.xml");
			addChild(nav);
		}
		//some more irrelevant functions here

		//the function I need to call from the Navigation Class
		public function portfolioXML(newXML:String):void {
			portfolio=new Portfolio(newXML);
			contentContainer.addChild(portfolio);
		}
	}
}

The code from Navigation class (located in /be/bundl)

//inside the btnClick function
var test:Bundl = new Bundl();
test.portfolioXML(_someVar)

Which results in an :
Error: Error #2136: The SWF file file:///Macintosh%20HD/Users/cerbellum/Projects/Bundl/site/FINAL/FULL.swf contains invalid data. at be.bundl::Navigation/btnClick()

I’m guessing this is due to the fact that I’m calling the parent class in a child or something like that, but how do I get this done otherwise? I must totally be overlooking something here.

Thanks in advance,
Kevin