Change Password Code sample please?

[eluser]rd13[/eluser]
Hello everyone! can someone give me some idea on how to change password in codeigniter, example is when a user wants to change he's password, he needs to input his current password to add a new one. It's just like a typical updating passwords. Thank you!

[eluser]CroNiX[/eluser]

Code:

$data['password'] = 'the_new_password';

$this->db
  ->where('user_id', $user_id)
  ->update('table_name', $data);