function onSourceDownloadProgressChanged(sender, eventArgs) {

    var p = $get("Xaml1").content;
    var pc = Math.round((eventArgs.Progress * 100));
    p.findName("TextePourcentage").Text = "" + pc + "%";
    p.findName("progressBar")["Canvas.Left"] = -155 + eventArgs.Progress * 280;
    p.findName("ContainerBullePourcentage")["Canvas.Left"] = 15 + (eventArgs.Progress * 235);
}