Why is timer not stopping?

Here's my code:

var TIMER_DELAY:Timer = new Timer(3000, 1); // 8 second delay
TIMER_DELAY.addEventListener(TimerEvent.TIMER, EXMove);
function EXMove(event:TimerEvent):void
{
//To slide in on X axis
slideXTween = new Tween(EX1_mc, "x", Regular.easeOut, 882, 499, 2, true);
}
TIMER_DELAY.start();

After the first run, I want the tweening to stop but it didn't.

Here's my .fla file.