[AS3] écouteur clavier ne fonctionnepas

package { 
	import flash.display.MovieClip;
	import flash.events.*;
	import flash.ui.Keyboard;
	
	public class Vaisseau extends MovieClip{ 
	 
			
		public function Vaisseau(x1:Number,y1:Number) { 
			this.x=x1;
			this.y=y1;
			this.addEventListener(KeyboardEvent.KEY_DOWN, deplacement);
			this.addEventListener(Event.ENTER_FRAME, masterLoop);
		} 
	   	
		public function masterLoop(e:Event):void {
			trace(50);
			this.x+=1;
		}
		
		public function deplacement(evt:KeyboardEvent):void
		{
			trace(252);
			
		}
			
  	}
}