function progress($resource,$download_size, $downloaded, $upload_size, $uploaded)
{
    static $old = -1;
    if ($downloaded > $old) {
        $old = $downloaded;

        $percent = ($download_size) ? $downloaded / $download_size  * 100 : 0;
        $percent = round($percent, 2);
        echo "\rdownload: $percent%                  \r";
    }
}