-----CONTROLLER

public function check(){
		$this->lang->load('login_label', $this->session->userdata('tms_site_lang'));
		$user = $_POST['tx_user'];
		$password = $_POST['tx_password'];

		$this->load->model('user_model');
		$query = $this->user_model->check($user, $password);
		$op = $query['op'];

		if($op == 1){
			$data['user'] = $query['res'][0];
			$this->session->set_userdata('tms_user_id', $data['user']->id);
			$name = $data['user']->name.' '.$data['user']->lastname;
			$this->session->set_userdata('tms_user_name', $name);
			$this->session->set_userdata('tms_user_rol', $data['user']->rol);
			if($this->session->userdata('tms_user_rol') != 5){
				redirect(base_url().'main/', 'refresh');
			}else{
				redirect(base_url().'employees/', 'refresh');
			}
		}else{
			if($op == 4){
				$data['user'] = $query['res'][0];
				$this->session->set_userdata('tms_user_id', $data['user']->id);
				$this->session->set_userdata('tms_client_id', $data['user']->client_id);
				$name = $data['user']->name.' '.$data['user']->lastname;
				$this->session->set_userdata('tms_user_name', $name);
				$this->session->set_userdata('tms_user_rol', $data['user']->rol);
				redirect(base_url().'main/', 'refresh');
			}else{
				$msg = $this->lang->line($query['res']);
				$this->session->set_flashdata('error_msg', $msg);
				//echo $this->session->flashdata('error_msg');
				redirect(base_url().'user/', 'refresh');
			}
		}
	}


---- MODELO

public function check($user, $password){
		$where = array('email' => $user);
		$this->db->select('*');
		$this->db->from('usuarios');
		$this->db->where($where);

		$q = $this->db->get();
		if($q->num_rows > 0){
			$q = $q->result();
			$pwd_plain = $this->encrypt->decode($q[0]->password);
			if($pwd_plain == $password){
				$op = 1;
				$res = $q;
			}else{
				$op = 2;
				$res = 'login_incorrectinfo';
			}
		}else{
			$this->db->select('*');
			$this->db->from('employee');
			$this->db->where($where);
			$q = $this->db->get();
			if($q->num_rows > 0){
				$q = $q->result();
				$pwd_plain = $this->encrypt->decode($q[0]->password);
				if($pwd_plain == $password){
					$op = 4;
					$res = $q;
				}else{
					$op = 2;
					$res = 'login_incorrectinfo';
				}
			}else{
				$op = 3;
				$res = 'login_doesnexist';
			}
		}

		return array('op' => $op, 'res' => $res);
	}