title: jqueryui autocomplete not working/working depending on the domain identical JSONP is served from - why?
body: <p>The code is below, directly taken from the jqueryui autocomplete example. The only change is that it's picking up the JSONP from my own site, except it does nothing except stay on the little spinner whilst looking for a response.</p>
  
  <pre><code>$( "#birds" ).autocomplete({
    source: function( request, response ) {
      $.ajax( {
        url: "http://www.galaxygraphics.co.uk/fresnius_jsonp.php",
        dataType: "jsonp",
        data: {
          term: request.term
        },
        success: function( data ) {
          response( data );
        }
      } );
    },
    minLength: 3,
    select: function( event, ui ) {
      log( "Selected: " + ui.item.value + " aka " + ui.item.id );
    }
  } );
  </code></pre>
  
  <p>If I change the source of the JSONP to</p>
  
  <p>url: "<a href="https://jqueryui.com/resources/demos/autocomplete/search.php" rel="nofollow noreferrer">https://jqueryui.com/resources/demos/autocomplete/search.php</a>",</p>
  
  <p>..then it's all working OK. So the question is, what's different between the JSONP served in the jqueryUI example and my own page's JSONP? Both are served as text/html mime type and I see no differences at all either in the page as displayed, the data, the source or the headers.</p>
  
  <p><a href="https://jqueryui.com/resources/demos/autocomplete/search.php" rel="nofollow noreferrer">https://jqueryui.com/resources/demos/autocomplete/search.php</a>, = OK
  <a href="http://www.ggfxserve.co.uk/fresnius/fresnius_jsonp.php" rel="nofollow noreferrer">http://www.ggfxserve.co.uk/fresnius/fresnius_jsonp.php</a>, = Not OK, even though identical.</p>
  
  <p>If you want to test with the autocomplete form to see it in action (or not):-</p>
  
  <p><a href="http://www.ggfxserve.co.uk/fresnius/autocomplete.html" rel="nofollow noreferrer">http://www.ggfxserve.co.uk/fresnius/autocomplete.html</a> = working
  <a href="http://www.ggfxserve.co.uk/fresnius/autocomplete2.html" rel="nofollow noreferrer">http://www.ggfxserve.co.uk/fresnius/autocomplete2.html</a> = not working. Type "com" into either to start them off trying to autocomplete.</p>