What's wrong with my jQuery and twilio code?

I went to these two ( 1 , 2 ) for one of my projects.
I am on PHP. So I'm not sure how to do this.
I got an SSL certificate error one day while trying to test it. My SMS messages are not being sent.
I don't get any response or warning or anything when I test it with my HTML.
Please help me if there is a twilio and PHP expert . this is the form i am using in HTML

<form id="frm" name="frm">
   <div class="form-group">
      <label for="tel">Phone:</label>
      <input type="tel" class="form-control" id="phoneNumber" name="phoneNumber" required>
   </div>
   <button class="btn" type="submit" id="submit">Submit</button>
</form>

      

        
        
        
      

    

My script

$("#frm").submit(function(e){
   e.preventDefault();
   $.post("sendnotifications.php", $("#frm").serialize(),
   function(data){
   if(data.sms_sent == 'OK'){
   alert("Message Sent");
   } else {
   alert("Message Not Sent");
   }
   }, "json");
});

      

        
        
        
      

    

and here is my sendnotifications.php file

<?php/* Send an SMS using Twilio. You can run this file 3 different ways:


*
 * - Save it as sendnotifications.php and at the command line, run
 * php sendnotifications.php
 *
 * - Upload it to a web host and load mywebhost.com/sendnotifications.php
 * in a web browser.
 * - Download a local server like WAMP, MAMP or XAMPP. Point the web root
 * directory to the folder containing this file, and load
 * localhost:8888/sendnotifications.php in a web browser.
 */

// Step 1: Download the Twilio-PHP library from twilio.com/docs/libraries,
 // and move it into the folder containing this file.
 require "Services/Twilio.php";

// Step 2: set our AccountSid and AuthToken from www.twilio.com/user/account
 $AccountSid = "ACexxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
 $AuthToken =  "fafyyyyyyyyyyyyyyyyyyyyyyyyyyyyy";

// Step 3: instantiate a new Twilio Rest Client
 $http = new Services_Twilio_TinyHttp(
    'https://api.twilio.com',
    array('curlopts' => array(
        CURLOPT_SSL_VERIFYPEER => true,
        CURLOPT_SSL_VERIFYHOST => 2,
    ))
);

 $client = new Services_Twilio($sid, $token, "2010-04-01", $http);

// Step 4: Get phone number from the test-sms form
 $phone=$_POST["phoneNumber"];

// Step 5: Create SMS
 $sms = $client->account->sms_messages->create(

// Change the 'From' number below to be a valid Twilio number
 // that you've purchased, or the (deprecated) Sandbox number
 "717-xxx-xxxx",

// the number we are sending to - Any phone number
 $phone,

// the sms body
 "Get our app now: http://example.com/ourapp"
 );

// Display a confirmation message on the screen
 $sms_check='OK'; //Use Twilio callback here
 $return_json = '{"sms_sent":"' . $email_check . '"}';

echo $return_json;
?>  

      

        
        
        
      

    

Please tell me what I need to change to get my site working.
I changed $ http in sendnotifications.php after going to github faq twilio to prevent ssl certificate error. What else do I need to do?

Edit: I solved the problem using the code below.

    <?php 
// Step 1: Download the Twilio-PHP library from twilio.com/docs/libraries,
// and move it into the folder containing this file.
 require_once "Services/Twilio.php";
// Step 2: set our AccountSid and AuthToken from www.twilio.com/user/account
 $AccountSid = "ACxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
 $AuthToken = "04dxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
 // Twilio REST API version
 $version = "2010-04-01";
// Step 3: instantiate a new Twilio Rest Client
 $client = new Services_Twilio($AccountSid, $AuthToken, $version);
// Step 4: Get phone number from the test-sms form
 $phone=$_POST["phoneNumber"];

try{
$message = $client->account->messages->create(array(
    "From" => "+1xxxxxxxxxx",
    "To" => $phone,
    "Body" => "This code is for testing!",
));
$sms_check='OK';
}
catch (Exception $e) {
    $sms_check = 'Error';
}
$return_json = '{"sms_sent":"' . $sms_check . '"}';
echo $return_json;
?>

      

        
        
        
      

    

But now I am getting an error on my server.
SMS is being sent but this error appears.

Error: Could not decode response body as JSON. This probably indicates a server error 500

Does anyone know any way to solve this problem. My site is hosted on altervista.

Edit I solved the 500 error

By replacing the tinyHttp.php file inside "Services / Twilio" with the edited tinyhttp.php file from github .. The link of the edited github file is in the comments section.