What's the php code for if voted cant vote again for 1hour?

I have this vote dj script but it doesnt warn them when trying to vote again before 1 hour is over here is how its formatted.

PHP Code:

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        // Is this a valid link?
        if ( ! isset($ccount_database[$id]) )
        {
            die('Link with this ID not found');
        }

        // Increse count by 1
        $ccount_database[$id]['C']++;

        // Is this a unique click or not?
        if ( ! isset($_COOKIE['ccount_unique_'.$id]) )
        {
            $ccount_database[$id]['U']++;
        }

        // Update the database file
        rewind($fp);
        fwrite($fp, "<?php die();//" . serialize($ccount_database));
    }
    else
    {
        // Lock not successful. Better to ignore than to damage the log file
        die('Error locking file, please try again later.');
    }

    // Release file lock and close file handle
    flock($fp, LOCK_UN);
    fclose($fp);

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