手賤把代碼刪了一部分，添加回去的時(shí)候就不能用了，怎么辦呀？

原代碼：
<div class="collapse navbar-collapse">

            <ul class="nav navbar-nav navbar-left">
                {php global $top_nav}
                {loop $top_nav $nav}
                <li {if FRAME == $nav['name'] && !defined('IN_MODULE')} class="active"{/if}><a href="{if empty($nav['url'])}{php echo url('home/welcome/' . $nav['name']);}{else}{$nav['url']}{/if}" {if !empty($nav['blank'])}target="_blank"{/if}>{$nav['title']}</a></li>
                {/loop}
            </ul>
            <ul class="nav navbar-nav navbar-right">
                {template 'common/header-notice'}
                <li class="dropdown">
                
                
                
                

我刪掉的部分：
if empty($nav['url'])}{php echo url('home/welcome/' . $nav['name']);}{else}{$nav['url']}{/if}" {if !empty($nav['blank'])}target="_blank"{/if}>{$nav['title']

添加回去就徹底打不開了，網(wǎng)頁提示：
Not Found

The requested URL /web/{} was not found on this server.