Checking if posts exist in category when listing

I want to have a check if posts with some Category exist, and then list the contents of it on a page, and if not to make some simple message (like: No current posts in this category). How to make this conditional statement? I have a loop showing the posts like this:

<?php
$myposts = get_posts('posts_per_page=-1&category=9');
foreach($myposts as $post) :
  setup_postdata($post); ?>

<div class="art-PostContent">
 <h3 class="art-PostHeader"> <?php  the_title(); ?> </h3>
 <?php the_content(); ?>

</div>

<?php endforeach;  ?>