How come when I tried to assign the x and y of a duplicated 'laser1' mc to the xy of the movie clip inside a movieclip, the xy of the laser mc is zero. (sorry for the bad english)

The movie clip(cannonmc) that contains the script is inside another movie clip(cannon) followed by a 'ship' mc.

This is the script of the 'cannonmc' mc.
Code:
onClipEvent(load) {
	shots = 0;
}
onClipEvent(enterFrame) {
	if(Key.isDown(Key.SPACE)) {
		duplicateMovieClip(_root.laser1, "shootlas1"+shots, 7000+shots);
		_root["shootlas1"+shots]._x = this._x+20;
		_root["shootlas1"+shots]._y = this._y+10;
		if(shots != 99) {
			shots++;
		} else { shots = 0; }
	}
}
When 'ship' mc moves, the duplicated movie doesn't follow the moved 'cannon' mc.

Please help me.