I need some help in SMS API script for PHP.

Hello, I have written a PHP script which sends SMSes using FreeSMSAPI. But, I want to parse the JSON API response in PHP. I want some fields from JSON, like the mobile number, etc. By default, it shows the default message. I want to show my own message when message gets sent or fails.
The API response in JSON comes like this:

{
    "response":{
        "success":{
            "message":"Message Send Successfully",
            "number":["9699419699","9892098920"]
        }
    }
}

HTML:

My script written in PHP:

<?php
$skey = "mysecretkey";
$tonumber = $_POST['recnumber'];
$tomessage = $_POST['message'];
$response = file_get_contents("http://s2.freesmsapi.com/messages/send?skey=$skey&message=".urlencode($tomessage)."&senderid=MyID&recipient=$tonumber&format=json");
$json_a = json_decode($response);

if($json_a->status === "success")
{
echo $json_a->number;
}
else
{
echo 'Message not sent.';
}
?>

HTML:

When I use the above PHP code, it doesn't show anything. It shows only blank page.

 

Finally, you had better use print_r($json_a); thus you can see array. After, you write output to here.

 

You mean, I should change "echo" to "print" ?