Print Bitmap

Would you like to learn how to print files from a key frame, Bitmap found a script he most print automatically, wanted from printing only when clicked the button.

the script is this

print_bt.addEventListener(MouseEvent.CLICK, printThis);
function printThis(e:MouseEvent):void
{
var myPrintJob:PrintJob = new PrintJob();
myPrintJob.start();
myPrintJob.addPage(card);
myPrintJob.send();
}

var bd :BitmapData = new BitmapData(stage.stageWidth, stage.stageHeight, false);
bd.draw(stage);
var b:Bitmap = new Bitmap (bd);
var card:Sprite = new Sprite();
card.addChild(b);


var myPrintJob:PrintJob = new PrintJob();
myPrintJob.start();
myPrintJob.addPage(card);
myPrintJob.send();