Sending json to php server using jquery ajax - json error
<p>I have problem with my form on my webpage. I am trying to use ajax and json to send the form values to php server, but I can't make properly json object. </p>

<p><strong>My JS code</strong>   </p>

<pre><code>function sendJsonOpenPopout () {
    $('.submitBtn').click(function(e){
        e.preventDefault();

        var subject = $('.subject').val();
        var email = $('.email').val();
        var message = $('.message').val();

        var dataObject = {
            subject: subject,
            email: email,
            message: message
        }

        $.ajax({
        type: 'POST',
        url: '../../kontakt.php',
        contentType: "application/json",
        dataType: 'json',
        data: dataObject,

        success: function(data){
             alert('Items added');
        },

        error: function(){
            console.log('You have fail');
        }

        //success: function(){
            //var createdDiv = '&lt;div class="divToBeCentered"&gt;&lt;p class="dataText"&gt;Wiadomość została wysłana pomyślnie.\brDziękuję za kontakt.&lt;/p&gt;&lt;/div&gt;';
             //$('body').append(createdDiv);
         //}
    });
});
</code></pre>

<p><strong>My PHP code</strong></p>

<pre><code>&lt;?php 
    $str_json = file_get_contents('php://input'); //($_POST doesn't work here)
    $response = json_decode($str_json, true); // decoding received JSON to array
    $subject = $response[0];
    $from = $response[1];
    $message = $response[2];

    $to = "lubycha@gmail.com"; 
    $subject = $_POST['subject'];
    $from = $_POST['email'];
    $message = $_POST['message'];
    $headers = "Content-Type: text/html; charset=UTF-8"; 
    mail($to,$subject,$message,$headers);
?&gt;
</code></pre>

<p>I know there is similar question already asked, but the answers didn't help me.</p>

<p>Thanks for helping.</p>