POPUP

<div id="pop" style="position: absolute; z-index: 10000;  padding-top: 100px; margin: auto; height: 3000px; background: rgba(0,0,0,.5);">
<div style=" width: 300px; height: 200px; margin-left: auto; margin-right: auto; height: 300px; background: white; padding: 20px;">TESTO<br><br>
    <a href="http://www.usanautica.net">GO TO NEW SITE</a><br><br>
    <div id="stay"><a href="">GO TO OLD SITE</a></div><br>
</div>
</div>


  
<script src="http://code.jquery.com/jquery-latest.js"></script>

<script> 
$('#stay').click(function() {
  $('#pop').hide('slow', function() {
 
  });
});   
</script>