AJAX.call是否可以在除Firefox外的所有浏览器中使用？

Question

I am having a problem with an ajax load in firefox? I keep getting this message 'unreachable code after return statement' I have looked for what it is but cant really get to the bottom of it. It works well in edge, chrome, safari etc. Its just a button that when clicked loads a php page and displays in a div. The code is here with added alert. When in firefox it works sometimes or takes forever to load or not at all? Has anyone else came across this problem? Any help appreciated.

 $(document).ready(function(){
    $(".mainstuff button").click(function(){
        $('#loader').show();
        status = $(this).attr("data-name");
        var new_url = "demo_text.php?job_id="+status;
        //alert(status);
        $("#div1").load(new_url);

    });
});

$(document).ajaxStop(function() {
  alert("LOADED");
  $('#loader').hide();
  return true;
});

Answer 1

As strange as it sounds, I fixed the problem by taking out google analytics code which wa causing the problem. Wierd!