title: echo inside an echo - does it work?
body: <p>It's been a long time since I have done php so sorry for the silly question.</p>
  
  <p>This is my current code, I'm trying to save the URL as a variable so that I can insert it into the echo, but it doesn't seem to work as nothing appears:</p>
  
  <pre><code>&lt;?php ob_start();
  echo get_post_meta($post-&gt;ID, 'oldurl', true);
  $old_url = ob_get_contents();
  ob_end_clean();
  ?&gt;
  
  &lt;?php echo do_shortcode('[fbcomments][fbcomments url="$old_url" width="375" count="off" num="3" countmsg="wonderful comments!"]'); ?&gt;
  </code></pre>
  
  <p>I have echoed <code>$old_url</code> and can see that it has the correct value, but how do I insert the value into the <code>echo do_shortcode</code> with <code>url="$old_url"</code>?</p>
  
  <p>This doesn't work either:</p>
  
  <pre><code>&lt;?php echo do_shortcode('[fbcomments][fbcomments url="echo $old_url;" width="375" count="off" num="3" countmsg="wonderful comments!"]'); ?&gt;
  </code></pre>