$ .ajax调用不工作，不显示错误消息

Question

I need your help on my simple script. I want when user click on image (with id="menu_en") to execute external script in php page (in my case english.php), but ajax call is not working. Even using "error:" statement "alert(xhr.status);" does not help me as alert is showing just "0" and hide in second... Where I'm wrong? Here is my code placed into the body of the page:

 <script src='jquery-1.11.3.min.js'></script>       
    <script>
        $(document).ready(function(){                       
            $('#menu_en').on('click',function(){                    
                var enID = '1';
                var url = 'index.php';                          

                $.ajax({
                    type:'POST',
                    dataType: 'JSON',
                    url:'english.php',                                  
                    data: {language_id: enID},
                    success:function(data){
                        alert('Success!');
                    },
                    error: function (xhr, ajaxOptions, thrownError) {
                        alert(xhr.status);
                    }

                });             
            });
        });
    </script>

Answer 1

you may not be returning a reply from english.php

$result = array(
  'msg' => true
);
echo json_encode($result);

also use complete in javascript code

<script>
    $(document).ready(function(){                       
        $('#menu_en').on('click',function(){                    
            var enID = '1';
            var url = 'index.php';                          

            $.ajax({
                type:'POST',
                dataType: 'JSON',
                url:'english.php',                                  
                data: {language_id: enID},
                success:function(data){
                    alert('Success!');
                },
                error: function (xhr, ajaxOptions, thrownError) {
                    alert(xhr.status);
                },
                complete: function (result) {
                    console.log(result);
                }

            });             
        });
    });
</script>

complete all kinds of results..