how to post special character?

[eluser]Tống Kiện Phi[/eluser]
forum have same bug in my case, so you can see my clip to understand what i mean:

Link Youtube: http://www.youtube.com/watch?v=xeIPzea1U...e=youtu.be
Link my website: http://tongkienphi.com/clip/error.html

Or you can test with CI new version:
Step 1: Download CI new version.
Step 2: Open application/views/welcome_message.php and paste this code:

Code:

<form method="post">
   <textarea  200px; height: 100px;" name="code"></textarea>
   <input type="submit" name="submit" value="submit" />
  </form>

Step 3: Open application/controllers/welcome.php and paste this code:

Code:

public function index()
{
  $post = $this->input->post();
  echo $post['code'];
  $this->load->view('welcome_message');
}

Step 4: run http://localhost/ci and paste this code in my clip and then submit