title: How do I grey out and show a loading GIF in the centre of a table
body: <p>How do I  make a whole <code>&lt;table&gt;</code> have a transparent grey effect whilst a loading image shows in the middle?</p>
  
  <p>I want to run some AJAX calls and have the table inaccessible and overlayed with a grey background with a loading GIF in the centre whilst the ajax context is being loaded.</p>