Scrolling Text with mx.transitions.Tween

programming flash
1

I am creating a horizontal text scroller using the kirupa tutorial here http://www.kirupa.com/developer/actionscript/tween.htm my problem is I want it to scroll in an endless loop, and i’m stuck.
here’s the code

import mx.transitions.Tween;
import mx.transitions.easing.*;
loc1 = 708;
loc2 = 60/2;
_root.createEmptyMovieClip("scroll_mc", 0);
with (_root.scroll_mc) {
 moveTo(0, 0);
 lineTo(Stage.width, 0);
 lineTo(Stage.width, Stage.height);
 lineTo(0, Stage.height);
 endFill();
 
 createEmptyMovieClip("scrollMask",3);
 with(scrollMask){
 moveTo(108,21);
 beginFill(0x000088);
 lineTo(708,21);
 lineTo(708,60);
 lineTo(108,60);
 endFill();
 }
 
 createTextField("scrollText",2,loc1,loc2,10,10);
 with(scrollText){
 setMask(_parent.scrollMask);
 autoSize = true;
 textStr = "    |    ";
 for (var i = 0; i < (_global._data.length - 1); i++) {
 textStr = textStr + _global._id* + ": " + _global._data* + "    |    ";
 }
 text = textStr;
 }
 
 //create the tween
 var xPosT:Tween = new Tween(scrollText, "_x", Regular.easeOut, loc1, (0-scrollText.textWidth), (scrollText.textWidth * 1), false);
 xPosT.onMotionFinished = function() {
  trace("stopped");
 };
}