Relative coordinate issue in AS3 - actionscript-3

Question

I've edited the following code in order to let those green rectangles to follow my cursor which is customized by a small rectangle. But I've encountered several problems:
Although I haven't defined any coordinate in the separate class, but the size is abviously wrong in the stage when publish with only half size for the cursor coordinate.
The reset button cannot be activated, although I've tested well in the other code.
Here is the work I've published: http://neowudesign.com/hwu_ex04.html
The code on timeline
//hw//Creating a new cursor
newcursor.startDrag ("true");
Mouse.hide();
//hw//Creating a holder to hold the butterfly objects
var mothHolder = new Sprite();
addChild(mothHolder);
//hw//Creating seven moths at the beginning
makeMoths(7);
//hw//creating a function which can generate limited numbers of moths.
function makeMoths(MothsNumber:Number)
{
for (var i = 0; i < MothsNumber; i++)
{
newMoth = new Moth();
mothHolder.addChild(newMoth);
}
}
//hw//Set the reset button at the top for clicking, but it's failed to work;
//hw//Set the cursor back to the default one, and remove the custom one when hovering;
mothHolder.setChildIndex(reset,mothHolder.numChildren);
reset.addEventListener(MouseEvent.MOUSE_OVER, cursorchange);
function cursorchange(event:MouseEvent):void
{
Mouse.show();
newcursor.visible = false;
trace("alert!!");
}
//hw//creating a function of reset
reset.addEventListener(MouseEvent.CLICK, resetClick, false, 0, true);
function resetClick(evt:MouseEvent):void
{
removeChild(mothHolder);
mothHolder = new MovieClip();
addChild(mothHolder);
var numMoths:Number = Math.round(Math.random() * 6) + 1;
trace("Moths Numeber: "+ numMoths);
makeButterflies(numButterflies);
}
//hw//when the cursor leave the reset region, it turns back to the customized one
reset.addEventListener(MouseEvent.MOUSE_OUT, fl_MouseOutHandler);
function fl_MouseOutHandler(event:MouseEvent):void
{
removeEventListener(MouseEvent.MOUSE_OVER, cursorchange);
Mouse.hide();
newcursor.visible = true;
}
And the code for class "Moth" separately named "angle.as"
package {
import flash.display.MovieClip;
import flash.events.Event;
import flash.geom.Point;
public class angle extends MovieClip {
var speed:Number = 8;
function angle() {
//letting every moth follow the moving of the cursor
addEventListener(Event.ENTER_FRAME,mothMove);
function mothMove(myEvent:Event) {
trace(mouseX);
trace(mouseY);
var angle:Number = Math.atan2(mouseY - y, mouseX - x);
x += Math.cos( angle ) * speed;
y += Math.sin( angle ) * speed;
}
}
}
}