update using modal of bootstrap in codeigniter - codeigniter

Question

I have a problem when updating the password of student, I am using the modal of bootstrap: -> here is the picture updatepassword
here is my modal and the action is studentpasswordupdate/updatepasswordstudent, I retrieve the value using echo $Password in session
<div class="modal fade" id="myModal" role="dialog">
<div class="modal-dialog modal-lg">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal">×</button>
<h4 class="modal-title text-center">Change Password</h4>
</div>
<div class="modal-body"><br>
<form action="<?php echo site_url("studentpasswordupdate/updatepasswordstudent") ?>" method="POST">
<div class="l">
<label class=" input-lg" style="font-size: 28px;">Password:</label> <input class="k" type="text" name="Password" value="<?php echo $Password ?>" >
</div>
<br> <br><br>
<div class="modal-footer">
<button type="submit" name="Submit" class="btn btn-info m" >Save</button>
<button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
</div>
</form>
</div>
</div>
</div>
</div>
and here is my controller/method:
class Studentpasswordupdate extends CI_Controller {
//put your code here
function updatepasswordstudent(){
$id = $this->input->post('Id');
$data= array(
'Password' => $this->input->post('Password')
);
$this->db->where('Id', $id);
$this->db->update('studentinformation',$data);
$hasError = $this->db->_error_message();
echo $hasError;
redirect('studentform/index', 'refresh');
}
}

Answer 1

Try this
class Studentpasswordupdate extends CI_Controller {
function updatepasswordstudent()
{
$id = $this->input->post('Id');
$data = array(
'Password' => $this->input->post('Password')
);
$this->db->where('Id', $id);
if (!$this->db->update('studentinformation',$data))
{
$hasError = $this->db->_error_message();
echo $hasError;
}
else{
redirect('studentform/index', 'refresh');
}
}
}
In View
Set name field foe this
<input type="hidden" name="Id" value="<?php echo $Id ?>">