AS3 error - Help please...

I get this error message -

1037: Packages cannot be nested

1114: The public attribute can only be used inside a package.

Any ideas guys?

here's the code;

package  
{
import flash.display.*;
import org.papervision3d.cameras.Camera3D;
import org.papervision3d.objects.parsers.Sketchup;
import org.papervision3d.objects.parsers.SketchupCollada;
import org.papervision3d.scenes.Scene3D;	

public class Sketch extends PaperBase
{
	public var model:Sketchup;

	public function Sketch() 
	{
		stage.align = StageAlign.TOP_LEFT;
		stage.scaleMode = StageScaleMode.NO_SCALE;
		stage.quality = StageQuality.MEDIUM;
		init();
	}

	override protected function init3d():void 
	{
		model = new Sketchup("single_trainer.kmz");				
		model.scale = .01;

		default_scene.addChild( model );
	}

	override protected function processFrame():void 
	{
		model.rotationY +=  (((mouseX - (stage.stageWidth/2))/10) - model.rotationY) / 3;
		model.rotationX +=  ((-((mouseY-(stage.stageHeight/2))/10))-model.rotationX) / 3;               
	}

}

}