Ok the example that enpstudios lives here doesn´t exactly what I want. because I don´t want to load an image from a PC to the server. What I want is to load a drawing that a user do in the flash to a server. Finally I get it using sendToURL. The image loads correctly in the server,but I have one more problem, and is that I want a response if the draw loads correctly or if there was an error, and senToURL method haven´t any response. So I'm trying wiht URLLoader with this code:

Code:
private function guardarImg(e:MouseEvent):void
        {
            var canvasBmp:BitmapData = new BitmapData(606,516);
            canvasBmp.draw(canvas);
            var myEncoder:JPGEncoder = new JPGEncoder(100);
            var byteArray:ByteArray = myEncoder.encode(canvasBmp);

            canvasBmp.dispose();
            var header:URLRequestHeader = new URLRequestHeader("Content-type","application/octet-stream");

            var myDate:Date = new Date  ;
            var timeNow:Number = myDate.getTime();
            timeNow.toString();
           
            var request:URLRequest = new URLRequest("savejpg.php?nombre=images/draw_" + myDate + ".jpg");
            request.data = byteArray;
            request.method = URLRequestMethod.POST;
            var loader:URLLoader = new URLLoader();
            loader.dataFormat = URLLoaderDataFormat.VARIABLES;
            try
            {
                loader.load(request);
                showSaveMessage(msg);
            }
            catch (e:Error)
            {
                showFailMessage(fmsg);
            }
        }
But now nothing happens, no error is displayed and the drawing doesn't load.