Django/jQuery- get submit button value from multiple buttons

I have the next submit buttons inside a post form:

 <div class="col-md-4 col-sm-4">
     <button type="submit" class="btn btn-default btn-block" value="True" id="subButton" name="is_attending" onclick="FbotonOn()">Yes, i'm in!</button>
 </div>
 <div class="col-md-4 col-sm-4">
      <button type="submit" class="btn btn-default btn-block"  value="False" id="subButton" name="is_attending" onclick="FbotonOf()">Sorry, i can't!</button>
  </div>

And this jQuery:

$('#post-form').on('submit', function(e) {
        e.preventDefault();
        $("#subButton").click(function(e){
            e.preventDefault();
            var my_button = $(this).val();
            $.ajax({
            type : "POST",
            url: "{% url 'guest_update' %}",
            data: {
                guest_id : "{{ guest.guest_id }}",
                invites_names : $('#name').val(),
                phone_no : $('#phone').val(),
                best_wishes : $('#wishes').val(),
                with_partner : $('#myCheck:checked').val(),
                partner_name : $('#partner_name').val(),
                is_attending : my_button,
                csrfmiddlewaretoken: '{{ csrf_token }}',
                dataType: "json",
            },

            success: function(data){
                $('output').html(data.msg)
            },

            failure: function() {

            }
        });
        });

    });

Every time I try to submit a form and press the first button, it works, but the second one, it doesn't. I've tried also without the click function but if a press the second button, I receive the first one value. Where am I wrong?

UPDATE1 Swati was right. The same id for the buttons was the issue.

 <div class="col-md-4 col-sm-4">
     <button type="submit" class="btn btn-default btn-block" value="True" id="subButton" name="is_attending" onclick="FbotonOn()">Yes, i'm in!</button>
 </div>
 <div class="col-md-4 col-sm-4">
      <button type="submit" class="btn btn-default btn-block"  value="False" id="subButton2" name="is_attending" onclick="FbotonOf()">Sorry, i can't!</button>
  </div>