An Error Was Encountered The action you have requested is not allowed. [help]

[eluser]huskyfritz[/eluser]
Hi, I have a small CI app deployed in my localhost and it works fine. I am planning to deploy it in a web server but I always get an error "An Error Was Encountered. The action you have requested is not allowed.". I have a login form and when I try to validate the user, the said problem will appear.

Here's my little code:
login controller

Code:

function validate_User(){
// utilize validation helper
   $this->form_validation->set_rules('username','Username','trim|required|max_length[5]');
   $this->form_validation->set_rules('password','Password','trim|required|max_length[32]');

   if($this->form_validation->run() == FALSE){
      $data_array = array('dashboard_msg' => validation_errors());
      $this->session->set_flashdata($data_array);
      redirect('login');
   } else {
      $query = $this->functions_model->validate_credentials_model();

      if($query){
         redirect('controlpanel');
      } else {
         $data_array = array('dashboard_msg' => "<p> Access denied. Please try again.</p>");
         $this->session->set_flashdata($data_array);
         redirect('login');
      }
   }
}

Here's my view:

Code:

<div id="login">
   &lt;form action="http://domain.com/login/validate_user" method="post" accept-charset="utf-8"&gt;&lt;div>
      &lt;input type="hidden" name="csrf_test_name" value="f6df75341615931ce4cc651adf363aa4" /&gt;
</div>

<div id="log">
   <p id='login-header'>Please login here</p>
   <p class = 'pad-top-bottom'>
      <label for="username">Username</label>
      &lt;input type="text" name="username" value="" class = 'round username-password' id = 'login-username' placeholder = 'Username' /&gt;
   </p>
   <p class = 'pad-top-bottom'>
      <label for="password">Password</label>
      &lt;input type="password" name="password" value="" class = 'round username-password' id = 'login-password' placeholder = 'Password' /&gt;
   </p>

   &lt;input type="submit" name="submit" value="Login" class = "blue icon-left round" id="login-button" /&gt;&lt;a href="http://domain.coom#" id = 'anchor-forgot-password'>Forgot your password?</a></br></br>&lt;/form&gt;

</div>

Even I tried to display a text in my controller which looks like the code below, the problem still appears.

Code:

function validate_User(){

   die('message appears');

// utilize validation helper
   $this->form_validation->set_rules('username','Username','trim|required|max_length[5]');
   $this->form_validation->set_rules('password','Password','trim|required|max_length[32]');

   if($this->form_validation->run() == FALSE){
      $data_array = array('dashboard_msg' => validation_errors());
      $this->session->set_flashdata($data_array);
      redirect('login');
   } else {
      $query = $this->functions_model->validate_credentials_model();

      if($query){
         redirect('controlpanel');
      } else {
         $data_array = array('dashboard_msg' => "<p> Access denied. Please try again.</p>");
         $this->session->set_flashdata($data_array);
         redirect('login');
      }
   }
}

I've search over the net regarding this problem but cannot find a solution for this. Is it CSRF in codeigniter causing this problem? Is there any problem with my code that causing the error?

Thanks so much!