How to fix the error: Error # 2044: Unhandled IOErrorEvent :. text = Error # 2035: URL not found

I need to add listeners

var context:LoaderContext = new LoaderContext();
    context.checkPolicyFile = true; 

var url:URLRequest = new URLRequest("gallery/test.swf");

var myLoader:Loader = new Loader();
    myLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, onLoadComplete);
    myLoader.addEventListener(AsyncErrorEvent.ASYNC_ERROR, errorHandlerAsyncErrorEvent);
    myLoader.addEventListener(IOErrorEvent.IO_ERROR, errorHandlerIOErrorEvent);
    myLoader.addEventListener(SecurityErrorEvent.SECURITY_ERROR, errorHandlerSecurityErrorEvent);
    myLoader.contentLoaderInfo.addEventListener(Event.INIT, initHandler);
    myLoader.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, infoIOErrorEvent);
    myLoader.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, progressListener);

    myLoader.load( url,context );
    myLoader.load( url);



function progressListener (e:ProgressEvent):void{
   trace("Downloaded " + e.bytesLoaded + " out of " + e.bytesTotal + " bytes");
}
function initHandler( e:Event ):void{
  trace( 'load init' );
}
function errorHandlerErrorEvent( e:ErrorEvent ):void{
  trace( 'errorHandlerErrorEvent ' + e.toString() );
}
function infoIOErrorEvent( e:IOErrorEvent ):void{
  trace( 'infoIOErrorEvent ' + e.toString() );
}
function errorHandlerIOErrorEvent( e:IOErrorEvent ):void{
  trace( 'errorHandlerIOErrorEvent ' + e.toString() );
}
function errorHandlerAsyncErrorEvent( e:AsyncErrorEvent ) :void{
  trace( 'errorHandlerAsyncErrorEvent ' + e.toString() );
}
function errorHandlerSecurityErrorEvent( e:SecurityErrorEvent ):void{
  trace( 'errorHandlerSecurityErrorEvent ' + e.toString(
                                                        ) );
}
function onLoadComplete( e:Event ):void{
  trace( 'onLoadComplete' );
}