Problem With Undefined Property

Hey, I’m having a little trouble with the properties of an instance of a specific class. Here’s and example of the code I am using:

package {
    import flash.display.MovieClip;
    import flash.events.*;

    public dynamic class Circle1 extends MovieClip {
        private var _root:Object;
        public function Circle1() {
            addEventListener(Event.ADDED_TO_STAGE, beginClass);
            addEventListener(Event.ENTER_FRAME, eFrame);
        }
        private function beginClass(event:Event):void {
            _root=MovieClip(root);
        }
        private function eFrame(event:Event):void {
            this.x=_root.newCircle2.x;
            this.y=_root.newCircle2.x;
    }
}

This is in the class code for Circle1. Now here is the error that is being displayed int he Output Box when I try to run the file:

TypeError: Error #1010: A term is undefined and has no properties.
    at Circle1/eFrame()

Here’s the code that creates the two class instances as children on the Main Time Line:



if (spaceDown) {

        var newCircle1:Circle1=new Circle1();
        addChild(newCircle1);
    }
if (enterDown) {
        var newCircle2:Circle2=new Circle2();
        addChild(newCircle2);
    }

enterDown is a defined variable for the key press of Enter, and spaceDown is a defined variable for the key press of Space. Is there something I’m doing wrong here?