PHP类问题

Customer.inc文件类定义如下
<?php
class Customer{

var $customer_id;
var $customer_name;
var $fctype;
var $customer_age;
var $customer_sex;
var $customer_birthday;
var $customer_region;
var $customer_address;
var $customer_phone;
var $customer_email;
var $customer_qq;
var $customer_msn;
var $customer_source;
var $customer_state;
var $customer_create_date;
var $customer_last_consume_date;
var $image_path;
}?>调用
[code=PHP[
require_once 'class/Customer.inc';//此处报错终止了
$c = new Customer();
        $c->.....
/code]
为什么执行require_once就报错呢？