求教！Magento 模版调用不起作用

Question

求教~~文件: magento/app/design/fontend/default/your_theme/layout/customer.xml 
在次文件中<reference name="content">已经指明template的模版位置，但是我修改这个文件的内容然而页面一点反映也没有~~我已经将缓存关闭并删除所有缓存就是不起作用~~同样的问题还出现在checkout.xml文件指向的onepage页里面<block type="checkout/onepage_billing" name="checkout.onepage.billing" as="billing" template="checkout/onepage/billing.phtml"/>同样找到次路径下的billing.phtml修改依然不起作用~~求教是怎么回事~~我在后台设置中design选项全部都修改成了your_theme我所创建的主题了
<customer_account_login translate="label">
        <label>Customer Account Login Form</label>
        <!-- Mage_Customer -->
        <remove name="right"/>
        <remove name="left"/>        <reference name="root">
            <action method="setTemplate"><template>page/1column.phtml</template></action>
        </reference>
        <reference name="content">
            <block type="customer/form_login" name="customer_form_login" template="customer/form/login.phtml" />
        </reference>
    </customer_account_login>以下是文件: magento/app/design/fontend/default/your_theme/layout/chechout.xml 中部分
<reference name="content">
            <block type="checkout/onepage" name="checkout.onepage" template="checkout/onepage.phtml">
                <block type="checkout/onepage_login" name="checkout.onepage.login" as="login" template="checkout/onepage/login.phtml">
                    <block type="page/html_wrapper" name="checkout.onepage.login.before" as="login_before" translate="label">
                        <label>Login/Registration Before</label>
                        <action method="setMayBeInvisible"><value>1</value></action>
                    </block>
                </block>
                <block type="checkout/onepage_billing" name="checkout.onepage.billing" as="billing" template="checkout/onepage/billing.phtml"/>
                <block type="checkout/onepage_shipping" name="checkout.onepage.shipping" as="shipping" template="checkout/onepage/shipping.phtml"/>
                <block type="checkout/onepage_shipping_method" name="checkout.onepage.shipping_method" as="shipping_method" template="checkout/onepage/shipping_method.phtml">
                    <block type="checkout/onepage_shipping_method_available" name="checkout.onepage.shipping_method.available" as="available" template="checkout/onepage/shipping_method/available.phtml"/>
                    <block type="checkout/onepage_shipping_method_additional" name="checkout.onepage.shipping_method.additional" as="additional" template="checkout/onepage/shipping_method/additional.phtml"/>
                </block>
                <block type="checkout/onepage_payment" name="checkout.onepage.payment" as="payment" template="checkout/onepage/payment.phtml">
                    <block type="checkout/onepage_payment_methods" name="checkout.payment.methods" as="methods" template="checkout/onepage/payment/methods.phtml">
                        <action method="setMethodFormTemplate"><method>purchaseorder</method><template>payment/form/purchaseorder.phtml</template></action>
                    </block>
                </block>
                <block type="checkout/onepage_review" name="checkout.onepage.review" as="review" template="checkout/onepage/review.phtml"/>
            </block>
        </reference>