Warning: 1090: Migration issue...

[Anig]

Здравствуйте дорогие.
Пишу для клипа u1 такой скрипт

import flash.events.MouseEvent;

function onMouseMove(event:MouseEvent):void
{
var i:int;
i=(stage.mouseX==0)?1:stage.mouseX/100;
//trace(i);
u1.x=-150-i;

}
stage.addEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);

Флеш дает warning

Warning: 1090: Migration issue: The onMouseMove event handler is not triggered automatically by Flash Player at run time in ActionScript 3.0.  You must first register this handler for the event using addEventListener ( 'mouseMove', callback_handler).

Помогите понять пожалуйста, в чем дело?