title: Filter posts in slider
body: <p>At the minute my slider (s3Slider JQuery) calls and displays the last 5 posts. It grabs the images from a custom field labelled 'thumb'.</p>
  
  <p>I'd like instead for the slider to only call images that have a value in the 'thumb' custom field. Is this possible?</p>
  
  <p>Current query is...</p>
  
  <pre><code>&lt;?php
  $my_query = new WP_Query('showposts=5');
  while ($my_query-&gt;have_posts()) : $my_query-&gt;the_post();
  ?&gt;
  &lt;li class="sliderImage"&gt; &lt;a href="&lt;?php the_permalink() ?&gt;" rel="bookmark"&gt; &lt;img class="featimg" src="&lt;?php echo get_post_meta($post-&gt;ID, 'thumb', true) ?&gt;" alt="&lt;?php the_title(); ?&gt;"  /&gt;
  &lt;span class="des"&gt;&lt;h1&gt;&lt;?php the_title(); ?&gt;&lt;/h1&gt;&lt;?php the_excerpt(); ?&gt;&lt;/span&gt;    
  &lt;/a&gt;
  &lt;/li&gt;
  &lt;?php endwhile; ?&gt;
  </code></pre>
  
  <p>Thanks in advance.</p>