Adobe AIR - How can I download files from web server without save dialog

Hi I'm Leo Hyun from South Korea.

So I want to make downl开发者_JAVA技巧oader application using AIR. My web server has somefiles. I want to download that files and save my desktop without save dialog. I don't know how can I fix it. actually I'm just beginner for AIR.

I'm using Flash Builder 4 & Flex 4.0 & AIR 2.0.

Somebody help me plz!

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009" 
                   xmlns:s="library://ns.adobe.com/flex/spark" 
                   xmlns:mx="library://ns.adobe.com/flex/mx"
                   creationComplete="startApp();">

<fx:Declarations>
    <!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations> 

<fx:Script>
    <![CDATA[
        import flash.net.FileReference;

        private var fr:FileReference;
        private var urlRequest:URLRequest;

        private var downloadPDFFile:String="<!--MY WEB SERVER LOCATIONS-->/TEST.pdf";

        private function startApp():void
        {
            fr = new FileReference();
            urlRequest = new URLRequest();
        }

        private function DownloadFile():void
        {
            urlRequest.url = downloadPDFFile;
            fr.download(urlRequest);
        }

        protected function btnDownload_clickHandler(event:MouseEvent):void
        {
            // TODO Auto-generated method stub
            DownloadFile();
        }
    ]]>
</fx:Script>

<mx:Button verticalCenter="0" horizontalCenter="0" label="Download File ASD" id="btnDownload" click="btnDownload_clickHandler(event)"/>

</s:WindowedApplication>

Load the file contents using a URLLoader or HTTPService and write it to a file of your choice using the File and FileStream classes. Be careful not to overwrite user's own files.

//inside complete handler of the loader:
var file:File = File.documentsDirectory.resolvePath("test.txt");
var fileStream:FileStream = new FileStream();
fileStream.open(file, FileMode.WRITE);
fileStream.writeUTF(str);
fileStream.close();