import mx.events.DragEvent;
import mx.collections.ArrayCollection;
[Bindable]
public var isEnabled:Boolean = true;
private function creationHandler():void {
list1.dataProvider = new ArrayCollection(['A', 'B', 'C']);
list2.dataProvider = new ArrayCollection(['D', 'E', 'F']);
}
private function dragEnterHandler( evt:DragEvent ):void {
evt.target.dropEnabled = ( evt.target != evt.dragInitiator );
}