this._droptarget
this._droptargetはDragしたMCの下にあるMCを所得できる。
origX = garbage_mc._x;
origY = garbage_mc._y;
garbage_mc.onPress = function () {
this.startDrag ();
};
garbage_mc.onRelease = function () {
this.stopDrag ();
trace (this._droptarget);
if (this._droptarget == trashcan_mc) {
this._visible = false;
}
else {
this._x = origX;
this._y = origY;
}
};