Delete data by a form field

Code:

users model--
function no_of_users() {
$this->db->select("email");
$this->db->from("users");
return $this->db->get()->num_rows();
}

function select() {
$this->db->select("email");
$this->db->from("users");
$query=$this->db->get();
return $query;
}

function delete($email) {
$this->db->where("email", $email);
$this->db->delete("users");
return $this->db->affected_rows();
}

Controller--

Code:

public function index()
{
  $this->load->model('users');

  $data["select"]=$this->users->select();
  $this->load->view("view", $data);
}

public function delete(){

$email = $this->input->post('email',TRUE);
if($this->users->no_of_users($email)>0){
 $this->load->model('users');
 $this->users->delete($email);
$this->session->set_flashdata('msg','User-deleted');
}
else{
$this->session->set_flashdata('msg','No User with Such Email');
}
redirect(Controller/index);
}

View --

Code:

<?php
if($this->session->flashdata('msg')=='User-deleted'){
echo "Unsubscribed Succesfully";
}
?>

<form action="Controller/delete" method="post" id="form" name="form">
  <input id="email" name="email" type="email">
  <input name="submit" id="submit" type="submit" value="Unsubscribe">
</form>