How to use ajaxError

When ever an error occurs in an ajax call it fires ajaxError function. By examining the error details you'll be able to get an idea about the occurred error.

<script>
$( document ).ajaxError(function(event, xhr, options, exc) {
  alert('Couldn\'t load ' + options.url + ' because (' +
            xhr.status + ' - ' + xhr.statusText + ') ' + exc.message);
});
</script>