RemoveMovieClip dans API de dessin

this.createEmptyMovieClip("canvas_mc", this.getNextHighestDepth());

var a:Number = 0;
var mouseListener:Object = new Object();
mouseListener.onMouseDown = function() {
     this.isDrawing = true;
     this.orig_x = _xmouse;
     this.orig_y = _ymouse;
     this.target_mc = canvas_mc.createEmptyMovieClip("canvas_mc"+m, m);
};
mouseListener.onMouseMove = function() {
     if (this.isDrawing) {
          this.target_mc.clear();
          this.target_mc.lineStyle(1, 0xFF0000, 100);
          this.target_mc.moveTo(this.orig_x, this.orig_y);
          this.target_mc.lineTo(_xmouse, this.orig_y);
          this.target_mc.lineTo(_xmouse, _ymouse);
          this.target_mc.lineTo(this.orig_x, _ymouse);
          this.target_mc.lineTo(this.orig_x, this.orig_y);
     }
     updateAfterEvent();
};
mouseListener.onMouseUp = function() {
     this.isDrawing = false;
};
Mouse.addListener(mouseListener);


Merci d'avance et bonne année.