public static function destroyAllProgress()
    {
        // Get all filenames within the temporary folder
        $files = glob($tmpdir.'*');

        // Iterate through files
        $output = array();
        foreach ($files as $file) 
        {
            if (is_file($file)) 
            {
                // Return result to array
                $result = unlink($file);
                array_push($output, var_export($result, true));
            }
        }

        // If a file could not be deleted, return false
        if (array_search('false', $output)) 
        {
            return false;
        }

        return true;
    }