Printjob and convert Loader to sprite

1

Im working on a little project where I need to print images.
The images are externally loaded into the swf by using :

var imgLader:Loader = new Loader();
imgLader.load(new URLRequest("whatEverimage"));
addChild(imgLader);

I have this for my print button

printKnop.addEventListener(MouseEvent.CLICK, printen);
function printen(event:MouseEvent):void {
    var pj = new PrintJob();
    pj.start();

    pj.addPage(imgLader, {xMin:0,xMax:400,yMin:0,yMax:500});//die margins snap ik nog niet....
    pj.send();
    //delete pj;
}

But flash trows me an error

TypeError: Error #1034: Type Coercion failed: cannot convert flash.display::Loader@52d52791 to flash.display.Sprite.
at as3kleuterapp_fla::MainTimeline/printen()

Anyone an idea how to fix this ?