如何发布数据来查看不能发布的数据我得到了一个像未定义变量的错误

How to post datas to view can't post data i got an error like undefined variable...
This is my view... i got an error $nk undefined variable.. how to post data to view?

    <div class="messages">
                <ul>
                    <?php foreach ($nk as $msgs){
    //                    print_r($msg);
    //                    exit;
                        if($msgs['sender'] == '9789445528')
                        {
                    ?>
                    <li class="sent">

                        <p><?php echo $msgs['message'];?></p>
                    </li>
                    <?php }
                    else {?>
                    <li class="replies">

                        <p><?php echo $msgs['message'];?></p>
                    </li>
                    <?php }}?>
                </ul>
            </div>

This is my controller.....

public function index()
    {

        $this->load->model('chat_model');
        $data['ans']=$this->chat_model->chat_list();
//        $this->msg();
//        print_r($data);
//        exit;
        $this->load->view('chat_view',$data);
    }
    public function msg()
    {
        $receiver=$this->input->post('mobile');
        $sender='9789445528';
        $this->load->model('chat_model','nav');
        $data2['nk']=$this->nav->msg($receiver,$sender);
        print_r($data2);
        exit;
        $this->load->view('msg_view',$data2);

    }

You are exiting your script before the view is loaded. Right here:

    print_r($data2);
    exit;
    $this->load->view('msg_view',$data2);