Merge pull request #2208 from appleboy/userguide

fixed #2207 user guide error
diff --git a/user_guide_src/source/tutorial/news_section.rst b/user_guide_src/source/tutorial/news_section.rst
index b64ea2a..833e34e 100644
--- a/user_guide_src/source/tutorial/news_section.rst
+++ b/user_guide_src/source/tutorial/news_section.rst
@@ -68,7 +68,7 @@
 			$query = $this->db->get('news');
 			return $query->result_array();
 		}
-        
+
 		$query = $this->db->get_where('news', array('slug' => $slug));
 		return $query->row_array();
 	}
@@ -146,7 +146,7 @@
 	<?php foreach ($news as $news_item): ?>
 
 		<h2><?php echo $news_item['title'] ?></h2>
-		<div id="main">
+		<div class="main">
 			<?php echo $news_item['text'] ?>
 		</div>
 		<p><a href="<?php echo $news_item['slug'] ?>">View article</a></p>