Jquery how to display error message when having 401 Unauthorized error?

Question

How do I display an error message for the 401 Unauthorized error?

My jquery:

$('.ero').click(function(e) {
    e.stopPropagation();
    e.preventDefault();
            $.ajax({
        type: 'POST',
        url: '/stem_op/3',
        success:function(msg){
        $('.warning').fadeIn(500).css({
        display: 'block',
        position: 'absolute',
        left: position.left + 50,
        top: position.top - 25
    }).append(msg).addClass("active")}
        });      
});

Answer 1

You could use the statusCode map, from the docs -

A map of numeric HTTP codes and functions to be called when the response has the corresponding code. For example, the following will alert when the response status is a 404:

$.ajax({
  statusCode: {
    401: function() {
      alert('401 fired');
    }
  }
});

If the request is successful, the status code functions take the same parameters as the success callback; if it results in an error, they take the same parameters as the error callback.