<?php
class UserModel extends CI_Model {

public function login($user,$pass) {

  $query = $this->db->select('*')->from('tbl_user')
  ->where( array (
    'usr_username' => $user,
    'usr_password'=>$pass))
  ->count_all_results();
return $query;
}
}
 ?>




--------------------------------



<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Ajax extends CI_Controller {

	public function checklogin() {
    $username = $this->input->post('username');
    $password = $this->input->post('password');

		$result = $this->UserModel->login($username,$password);
		if($result > 0) {
      $arr = array('success'=>true,'data'=>$username);
    	echo json_encode($arr);
    } else {
      $arr = array('success'=>false,'data'=>'Username or password is incorrect.');
    	echo json_encode($arr);
	}

  }



}