McGansWebsite/admin/application/controllers/Welcome.php

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

class Welcome extends CI_Controller {
	
	public function __construct()
	{
		parent::__construct();
		$this->load->model('Common_model');
	}

	public function index()
	{
		$this->load->view('login');
	}
	
	public function dashboard()
	{
		
		$this->load->view('dashboard');
	}
	
	public function admin_login()
	{
		
		$username=$this->input->post('username');
		$password=$this->input->post('password');
	 
		$check=$this->Common_model->get_login_detail($username,$password);
	 
		if($check->num_rows()>0)
		{
			$ch	=$check->row();
			$this->session->set_userdata('username',$ch->username);
			$this->session->set_userdata('id',$ch->id);
			$this->session->set_userdata('suc',' Successfully Logged in..!');
			if($usertype!=2){
				redirect('dashboard');}
			else{
				redirect('dashboard');}
		}
		else
		{
			$this->session->set_userdata('err','The username or password is incorrect.');
			redirect('dashboard');
		}
		
	}
	public function logout()
	{
		$admin_id=$this->session->userdata('id');
		
        $data = array('id' => '', 'username' => '');
        $this->session->unset_userdata($data);
        $this->session->sess_destroy();
		redirect('');
	}
	 
}