ajaxStop /开始不起作用

I am building a Wikipedia viewer, I have this in my code:

$(document).ready(function() {         

    $(document).on('click', '#search_button', function() {          
      addWikiResults();          
    });

    $(document).keypress(function(enter) {
      if(enter.which == 13)
        addWikiResults();          
    });


    $(document).ajaxStop(function() { 
      alert('ajax stop now working');         
    });

  });

ajaxStop would not fire at all as well as ajaxStart. Everything works except that part. Here is my codepen: https://codepen.io/nuclearmachine/pen/xdXXKv?editors=1000 specifically line 130

Global events are never fired for cross-domain script or JSONP requests, regardless of the value of global.

http://api.jquery.com/category/ajax/global-ajax-event-handlers/