Código ActionScript :
import flash.events.MouseEvent;
texto_txt.text = null;
var loader2:URLLoader = new URLLoader (new URLRequest(MovieClip(root).variable2));
loader2.addEventListener(Event.COMPLETE, completeHandler);
function completeHandler (event:Event):void{
var loaderTXT2:URLLoader = URLLoader (event.target);
texto_txt.htmlText = loaderTXT2.data;
}
arriba2_mc.buttonMode = true;
arriba2_mc.addEventListener (MouseEvent.CLICK, UpScroll);
abajo2_mc.buttonMode = true;
abajo2_mc.addEventListener (MouseEvent.CLICK, DoScroll);
texto_txt.wordWrap = true;
//texto_txt.html = true;
var min:Number = controlador_mc.y;
var max:Number = min + (carril_mc.height - controlador_mc.height);
var intervalo:Number = max - min;
var arrastrando : Boolean = false;
var bounds: Rectangle = new Rectangle (controlador_mc.x, controlador_mc.y, 0, carril_mc.height - controlador_mc.height);
controlador_mc.addEventListener (MouseEvent.MOUSE_DOWN, arrastrandoScroll);
stage.addEventListener(MouseEvent.MOUSE_UP,detener);
function arrastrandoScroll (mouseEvent:MouseEvent){
controlador_mc.startDrag (false, bounds);
arrastrando = true;
controlador_mc.addEventListener (Event.ENTER_FRAME,progreso);
}
function UpScroll (mouseEvent:MouseEvent){
//subir scroll
}
function DoScroll (mouseEvent:MouseEvent){
//bajar scroll
}
function detener (mouseEvent:MouseEvent){
controlador_mc.stopDrag();
arrastrando = false;
}
function progreso (e:Event)
{
var moverScroll:Number = controlador_mc.y - min;
var porcent:Number = moverScroll/intervalo;
if (arrastrando == true){
texto_txt.scrollV = porcent * texto_txt.maxScrollV;
}
}
aqui esta el codigo a cuestión..