help with compiling error

package com.wiley.as3bible.printing {
    import flash.display.Sprite;
    import flash.text.TextField;
    import flash.text.TextFieldAutoSize;
    import flash.net.URLLoader;
    import flash.net.URLRequest;
    import flash.events.Event;
    import flash.printing.PrintJob;
   
    public class Printing extends Sprite {
       
        private var _printableContent:Sprite;
        private var _textField:TextField;
        private var _loader:URLLoader;
       
        public function Printing() {
           
            //Load the text from a text file
            _loader = new URLLoader();
            _loader.load(new URLRequest("http://www.rightactionscript.com/samplefiles/lorem_ipsum.txt"));
            _loader.addEventListener(Event.COMPLETE, completeHandler);
            //Create a multiline text field that autosizes.
            _textField = new TextField();
            _textField.width = 400;
            _textField.multiline = true;
            _textField.wordWrap = true;
            _textField.autoSize = TextFieldAutoSize.LEFT;
           
            //Create a sprite container for the text field,
            //and add the text field to it.
            _printableContent = new Sprite();
            addChild(_printableContent);
            _printableContent.addChild(_textField);
        }
       
        //When the text loads add it to the text field and  then print the text
        private function completeHandler(event:Event):void {
            _textField.text = _loader.data;
           
            var printJob:PrintJob = new PrintJob();
            if (printJob.start()) {
                printJob.addPage(_printableContent);
                printJob.send();
            }
        }
    }
}

the compiling error is:

1046: Type was not found or was not a compile-time constant: PrintJob.

1180: Call to a possibly undefined method PrintJob.

can anyone explain this to me?