function getShortUrl($longUrl)
{
    $bitly = new Bitly();
    $loginUsername = "******";
    $apiKey = "R_3619371f50c30a66315d1454eb046c2a";
    $bitly->setAuthentication($loginUsername, $apiKey);
    $shortUrl = $bitly->getShortURL($longUrl);
    return $shortUrl;
}