slideshow / image gallery in AS3, how do I stop the slideshow?

//timer/////////////////////////////////////////////
 
var autoRotate = 0;
var imageTimer:Timer = new Timer(5000);
imageTimer.addEventListener(TimerEvent.TIMER, readImages);
 
function readImages(event:TimerEvent):void{
if(autoRotate == 0){
	imageTimer.start();
	trace("fired");
		top.alpha = 100;
	img_holder.removeChildAt(0);
if(increment < total-1){
	increment += 1;
} else {
	increment = 0;
}
ImageLoad(LINKS[increment],img_holder,0,0); 
imageNUMB.text = increment+1 + " of " + total;
}
}
 
//////////////////////////////////////////////////
 
//loader//////////////////////////////////////////
import flash.display.*;
import flash.events.*;
import flash.net.URLRequest;
import flash.net.URLVariables;
import fl.transitions.Tween;
import fl.transitions.easing.*;
 
var numOfImages = 90;
var imgNum = 0;
 
 
function ImageLoad(u:String,target,Ypos,Xpos){
	var targetClip = target;
	var positionY = Ypos;
	var positionX = Xpos;
    var _loader:Loader = new Loader();
    var request:URLRequest = new URLRequest(u);
    _loader.load(request);
	 targetClip.addChild(_loader);
	 //targetClip.y = positionY;
	 //targetClip.x = positionX;
	 _loader.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, loadProgress);
	 _loader.contentLoaderInfo.addEventListener(Event.COMPLETE, completeHandler);
}
 
function loadProgress(event:ProgressEvent):void {
    var percentLoaded:Number = event.bytesLoaded/event.bytesTotal;
    percentLoaded = Math.round(percentLoaded * 100);
	if(percentLoaded > 20){
		trace("firing");
	preLoader.alpha = 100;
	} else{
	preLoader.alpha = 0;
	}
}
 
function completeHandler(event):void {
    trace("DONE");
	preLoader.alpha = 0;
	var myTween:Tween = new Tween(top, "alpha", Strong.easeOut, 1, 0, 1, true);
	imageTimer.start();
}
////////////////////////////////////////////////////
 
//xml load//////////////////////////////////////////
var loader:URLLoader;
loader = new URLLoader();
var increment = 0;
var total = 0;
var i = 0;
var TITLES = [];
var COPYS = [];
var LINKS = [];
 
//ADD EVENT LISTENER, THIS LISTENS FOR WHEN XML IS LOADED
loader.addEventListener(Event.COMPLETE, xmlLoaded);
 
//DEFINES XML FILE THAT IS LOADED
var request:URLRequest = new URLRequest("com_daybreakgarbett.xml");
loader.load(request);
 
//FUNCTON CALLED ONE XML IS LOADED
function xmlLoaded(event:Event):void {
   //DEFINE MY XML VARIABLE
   var myXML:XML = new XML(loader.data);
   total = myXML.children().length();
   trace(total);
   imageNUMB.text = "1 of " + total;
   ImageLoad(myXML.children().LINK[0],img_holder,0,0); 
   for (i=0; i<total; i++) {
		LINKS[i] = myXML.children().LINK.children()[i];
	}
}
////////////////////////////////////////////////////
 
//gallery//////////////////////////////////////////
btn1.addEventListener(MouseEvent.MOUSE_DOWN, showimg1); 
function showimg1(event:MouseEvent):void {
	top.alpha = 100;
	img_holder.removeChildAt(0);
ImageLoad(LINKS[0],img_holder,0,0);
increment = 0; //number makes the slideshow start at this image
imageNUMB.text = 1 + " of " + total;
}
 
btn2.addEventListener(MouseEvent.MOUSE_DOWN, showimg2); 
function showimg2(event:MouseEvent):void {
	top.alpha = 100;
	img_holder.removeChildAt(0);
ImageLoad(LINKS[1],img_holder,0,0);
increment = 1;
imageNUMB.text = 2 + " of " + total;
}
 
btn3.addEventListener(MouseEvent.MOUSE_DOWN, showimg3); 
function showimg3(event:MouseEvent):void {
	top.alpha = 100;
	img_holder.removeChildAt(0);
ImageLoad(LINKS[2],img_holder,0,0);
increment = 2;
imageNUMB.text = 3 + " of " + total;
}
 
btn4.addEventListener(MouseEvent.MOUSE_DOWN, showimg4); 
function showimg4(event:MouseEvent):void {
	top.alpha = 100;
	img_holder.removeChildAt(0);
ImageLoad(LINKS[3],img_holder,0,0);
increment = 3;
imageNUMB.text = 4 + " of " + total;
}