Suchfunktion "Warning"

<?php /* Don't remove this line. */ require('./wp-blog-header.php'); ?>
<?php get_header() ?>
<div id="main">
 <div id="content"> 
 <?php if (have_posts()) { ?> 
  <?php $post = $posts[0]; /* Hack. Set $post so that the_date() works. */ ?>
  <h3><?php _e('Suchergebnisse f&uuml;r '); echo '“<strong>'.$s.'</strong>”.'; ?></h3>   
  <div class="post-info"><?php _e('Gefunden was Du meintest?') ?></div>  
  <br/>    
  <?php while (have_posts()) { the_post(); ?>    
   <?php require('post.php'); ?>
  <?php } ?>
 <?php } else { ?>
  <h2 class="center"><?php _e('Nicht gefunden') ?></h2>
  <p><?php _e('Sorry, keinen Beitrag gefunden mit '); echo '“<strong>'.$s.'</strong>”.'; ?></p>
 <?php } ?>  
 </div>
 <div id="sidebar">
  <?php get_sidebar(); ?>
 </div>
<?php get_footer(); ?>