title: $_POST not working when passed variable from Ajax
body: <p>Please excuse the basic question, I am new to all of this, but I'm keen to learn and have been trying to get this working for about 7 hours in total. No luck. I'm hoping you can help!</p>
  
  <p>This is my Ajax call:</p>
  
  <pre><code>&lt;script type="text/javascript"&gt;
    FB.Event.subscribe('edge.create',
      function(response) {
      $.post("http://www.mydomain.com/fbtest.php", { category: "&lt;?php echo $vpostid; ?&gt;" } );
      }
    );
  &lt;/script&gt;
  </code></pre>
  
  <p>And this is my fbtest.php code:</p>
  
  <pre><code>&lt;?php
  /** Set up WordPress environment */
  require_once( './wp-load.php' );
  require_once( './wp-admin/admin-ajax.php' );
  require_once( './wp-includes/post.php' );
  
  $vcatid = $_POST['category'];
  
  $meta_val = get_post_meta($vcatid, 'fb_likes', true);
  
  $fbmetval = intval($meta_val);
  $fbmetval = $fbmetval + 1;
  
  update_post_meta($vcatid, 'fb_likes', $fbmetval);
  
  ?&gt;
  </code></pre>
  
  <p>Any ideas would be very much appreciated. I'm sure that I'm just missing something very basic.</p>
  
  <p>Thanks in advance,
  Rob</p>