I liked this plugin and I added thumbnail

hello thanks for this plugin I realized that it hasn’t thumbnail so after searching the internet and trying to change it I could change it as follow I am writing because maybe some one wanted the thumbnails like me
I changed after the for loop as follow:

foreach ( $postslist as $post ) :
					?>
		<?php //*********nickparsa?>
		<?php
			$thumb = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), 'thumbnail' );
			$url = $thumb['0'];
				?>
			<li><?php echo "<img src='".$url."'>";?> </li>
				<li><a href="<?php print get_permalink($post->ID); ?>" title="<?php  print get_the_title($post->ID); ?>"><?php  print get_the_title($post->ID); ?></a></li>