$(document).ready(function() {
  $('form').submit(function(event) {
    var data = JSON.stringify($(this).serializeField())
    var url = $(this).attr('action')

    $.ajax({
      type        : 'POST',
      url         : url,
      data        : data,
      dataType    : 'json',
      encode      : true,
    }).done(function(data) {
      alert("it workss");
    }).fail(function(data) {
      alert("it failed");
    });

    event.preventDefault();
  });
});

$.fn.serializeField = function() {
    var result = {};
    this.each(function() {
      $(this).find("> *").each(function() {
        var $this = $(this);
        var name = $this.attr("name");

        if ($this.is("fieldset") && name) {
           result[name] = $this.serializeField();
        }
        else {
           $.each($this.serializeArray(), function() {
               result[this.name] = this.value;
           });
        }
      });
    });
    return result;
};