function printOptions($program = null)
    {
        if (empty($program))
        {
            global $argv;
            $program = "{$argv[0]}";
        }
        echo str_repeat("=", 80)."\nUsage: {$program}\n".str_repeat("=", 80)."\n";
        $lines = $this->outputOptions();
        echo join( "\n" , $lines );
        echo "\n\n";
    }