ActionScript 3 code help?

Question

I am a newbie to flash and only know some simple stuff. I would appreciate some help please?
I'm trying to create a simple tween animation with button, the animation work perfectly,
The problem is that I want my animation, to play also if there is no button action... like a loop function or a replay?
There's my AS3 code
import fl.transitions.Tween;
import fl.transitions.easing.*;
var tmelX : Number = 0;
var coletteX : Number = -958;
var lakayX : Number = -1916;
var offerX : Number = -2874;
var xTween:Tween;
xTween = new Tween(content_mc,"x",Elastic.easeInOut,content_mc.x,coletteX,2,true);
var buttons : Array = [btn1,btn2,btn3,btn4];
for (var i:int = 0; i< buttons.length ; i++){
buttons[i].addEventListener(MouseEvent.MOUSE_OVER,navigate);
function navigate(event:MouseEvent):void{
switch (event.target){
  case (btn2) : setTween(coletteX);
  break;
  case (btn1) : setTween(tmelX);
  break;
  case (btn3)  : setTween(lakayX);
  break;
  case (btn4) : setTween(offerX);
  break;
function setTween(tweenX:Number):void
xTween.begin = content_mc.x;
xTween.finish = tweenX;
xTween.start();

Answer 1

// time between auto rollovers is idleTime+timeBetweenRollOvers (=5 seconds in example)
var idleTime:int = 4000;
// time between each buttons rollover
var timeBetweenRollOvers:int = 1000;
var t1:Timer=new Timer(idleTime,0);
t1.addEventListener(TimerEvent.TIMER,navF);
t1.start();
var buttonIndex:int;
var t2:Timer=new Timer(timeBetweenRollOvers,4);
t2.addEventListener(TimerEvent.TIMER,timerF);
function navF(e:TimerEvent):void{
buttonIndex=0;
t2.start();
function timerF(e:TimerEvent):void{
buttons[buttonIndex].dispatchEvent(new MouseEvent(MouseEvent.MOUSE_OVER));
buttonIndex++;
this.addEventListener(MouseEvent.MOUSE_MOVE,mousemoveF);
function mousemoveF(e:MouseEvent):void{
t2.reset();
t1.reset();
t1.start();
import fl.transitions.Tween;
import fl.transitions.easing.*;
var tmelX : Number = 0;
var coletteX : Number = -958;
var lakayX : Number = -1916;
var offerX : Number = -2874;
var xTween:Tween;
xTween = new Tween(content_mc,"x",Elastic.easeInOut,content_mc.x,coletteX,2,true);
var buttons : Array = [btn1,btn2,btn3,btn4];
for (var i:int = 0; i< buttons.length ; i++){
buttons[i].addEventListener(MouseEvent.MOUSE_OVER,navigate);
function navigate(event:MouseEvent):void{
switch (event.target){
  case (btn2) : setTween(coletteX);
  break;
  case (btn1) : setTween(tmelX);
  break;
  case (btn3)  : setTween(lakayX);
  break;
  case (btn4) : setTween(offerX);
  break;
function setTween(tweenX:Number):void
xTween.begin = content_mc.x;
xTween.finish = tweenX;
xTween.start();