Empty movieclip doesn't respond to events?

1

This code doesn’t do anything when I rolled over…

this.createEmptyMovieClip(“logo_mc”, this.getNextHighestDepth());

_root.logo_mc.onRollOver = function(){
trace(“rollover!!!”);
}

logo_mc.loadMovie(“http://www.macromedia.com/images/shared/product_boxes/80x92/studio_flashpro.jpg”);

Any clue??

Thx!