使用我的Web服务器发送短信

Please am creating a web application that sends sms alert when a user is registered. i wrote the script to do that which is below, i then uploaded that file to my web server for testing but it refuse to work. am actually having issues understanding curl. can someone tell me what am not doing right?

<?php

$number='08166848961';
$message_body='my test from server';

echo CURLsendsms($number,$message_body);

function CURLsendsms($number, $message_body){   

 $type='0';
 $routing='3';
 $token = 'VMnzTxbzgFKs5Po2vt6BhVt6VSWWNSDuaKAeI4Nch2cL4USf6furZ7ckVSc4Qf8jk';

    $api_params ='message='.$message_body.'&to='.$number.'&sender='.$number.'&type='.$type.'&routing='.$routing.'&token='.$token;  
    $smsGatewayUrl = "https://smartsmssolutions.com/api/?";  
    $smsgatewaydata = $smsGatewayUrl.$api_params;
    $url = $smsgatewaydata;

    $ch = curl_init();                       // initialize CURL
    curl_setopt($ch, CURLOPT_POST, false);    // Set CURL Post Data
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    $output = curl_exec($ch);
    curl_close($ch);                         // Close CURL

    // Use file get contents when CURL is not installed on server.
    if(!$output){
       return $output =  file_get_contents($smsgatewaydata);  
    }else
}   

?>