How to keep re-loading the same image, addchild problem

I need to reload the same JPG about every second for an indefinite time. Problem is that that right now with addchild it adds the JPG on top of the old one eventually running out of memory from adding so many JPG’s
Is there a way to specify with addchild() to replace the old one?

var pictLdr:Loader = new Loader();
var pictURL:String  = "img.jpg";
var pictURLReq:URLRequest = new URLRequest(pictURL);
pictLdr.contentLoaderInfo.addEventListener( Event.INIT , loaded)

function loaded(event:Event):void {
    var targetLoader:Loader = Loader(;

Basicly i need imagepreview to keep reloading the same JPG everysecond replacing the old one without a blink

I have that code inside a movie clip that expands for 1sec and then it repeats running the script again. Is there a better way to do it? How can I keep calling this load function otherwise?

Thank you!