<script type="text/javascript">             $(function () {                 $("#btnShow").bind("click", function () {                                                             var $this = $(this);                                                               $.getJSON("http://www.imooc.com/data/sport.json",function(data){                                                                           $this.attr("disabled", "true");                                                              $.each(data, function (index, sport) {                                 if(index==4)                                   $("ul").append("<li>" +sport["name"] + "</li>");                                                                                                            });                          });                 });             });         </script>