Class 'Globe\Connect\Sms' not found using Yii PHP Framework

[zeejay09]

Hi, I am using Yii PHP Framework.
Straight to the problem, here is my code:
<php
use Globe\Connect\Sms;

$sms = new Sms($sender, $access_token);
$sms->setReceiverAddress($number);
$sms->setMessage($message);
$sms->sendMessage();
?>

But I am getting an error, Class 'Globe\Connect\Sms' not found. I can't find any solution, can anyone help me?