[Q] retrieve a value from a Class

programming flash
1

dear all

i have create a simple class ABC

package {
   class ABC extends MovieClip {
      private var _id:Number;
      public function ABC() {
         this._id = 0;
      }
      public function setID(in_id:Number):void {
         this._id = in_id;
      }
      public function getID():Number {
         return this._id;
      }
   }
}

and a loop for assigning the ID

for (var i=0; i<10; i++) {
   var a:ABC = new ABC();
   a.name = "a" + i;
   a.setID(i);
   addChild(a);
}

what is the syntax, if i would like to retrieve the 3rd ID (that is MovieClip “a2”)
a2.getID(); // seems not working
MovieClip(root).a2.getID(); // not working as well

THANKS ~~