modaldialogAJAX

<script type="text/javascript">
            $(document).ready(function(){
                $("#simpan").click(function(){
                    var str = $('#id_form').serializeArray();
                    alert(str);
                    $.ajax({
                        type: "POST",
                        url: "<?php echo base_url();?>index.php/c_user/tambahuser",
                        data: str,
                        dataType: 'json',
                        success: function(data){
                            if(data.status == 'success'){
                                 alert('Berhasil');
                                }else{
                                 alert('Gagal');

                                }
                        }
                    });
                });
            });
        </script>

<!-- ------------------ HTML FORM ----------------->

<form action="" class="form-horizontal" id="id_form" method="POST">
                                        <div class="form-actions top">
                                            <div class="row">
                                                <div class="col-md-offset-3 col-md-9">
                                                </div>
                                            </div>
                                        </div>
                                        <div class="form-body">
                                            <!-- separated -->
                                            <div class="form-group">
                                                <label class="col-md-3 control-label">NIPAS</label>
                                                <div class="col-md-4">
                                                    <input type="text" class="form-control" name="nipas" id="nipas" placeholder="Enter text">
                                                </div>
                                            </div>
                                            <!-- separated -->
                                            <!-- separated -->
                                            <div class="form-group">
                                                <label class="col-md-3 control-label">Username</label>
                                                <div class="col-md-4">
                                                    <input type="text" class="form-control" name="username" id="username" placeholder="Enter text">
                                                </div>
                                            </div>
                                            <!-- separated -->
                                            <!-- separated -->
                                            <div class="form-group">
                                                <label class="col-md-3 control-label">Password</label>
                                                <div class="col-md-4">
                                                    <input type="password" class="form-control" name="password" id="password" placeholder="Enter text">
                                                </div>
                                            </div>
                                            <!-- separated -->
                                            <!-- separated -->
                                            <div class="form-group">
                                                <label class="col-md-3 control-label">Konfirm Password</label>
                                                <div class="col-md-4">
                                                    <input type="password" class="form-control" name="kpassword" id="kpassword" placeholder="Enter text">
                                                </div>
                                            </div>
                                            <!-- separated -->
                                            <!-- separated -->
                                            <div class="form-group">
                                                <label class="col-md-3 control-label">Jabatan</label>
                                                <div class="col-md-4">
                                                    <input type="text" class="form-control" name="jabatan" id="jabatan" placeholder="Enter text">
                                                </div>
                                            </div>
                                            <!-- separated -->
                                        </div>
                                        <div class="form-actions fluid">
                                            <div class="row">
                                                <div class="col-md-offset-3 col-md-9">
                                                    <button type="button" class="btn green" id="simpan">Simpan</button>
                                                    <!--<button type="submit" class="btn green">Simpan & Kirim</button>-->
                                                    <button type="reset" class="btn default">Batal</button>
                                                </div>
                                            </div>
                                        </div>
                                    </form>