codelgniter login check help

[eluser]shivi[/eluser]
i made my login model and when i click on login it gives me thius error

my login model code

Code:

<?php
class Login_model extends CI_Model{
    
    public function Login_model(){
        $this->__construct();
    }

    public function __construct(){
        parent::CI_Model();
    }


    public function checklogin($username,$password){
        
        $query = ("SELECT id FROM users_register WHERE username = ? AND password = ?");
        $result = $this->db->query($query,array($username,$password));
        
        if($result->num_rows() == 1){
            return $result->row(0)->id;
        }else{
            return false;
        }
    }
}

Code:

Fatal error: Call to undefined method CI_Model::CI_Model() in /var/www/mvckhalsanet/application/models/login_model.php on line 9