$(function() {

    $.ajaxSetup({

        error: function(jqXHR, exception) {

            if (jqXHR.status === 0) {

                alert('Not connect.\n Verify Network.');

            } else if (jqXHR.status == 404) {

                alert('Requested page not found. [404]');

            } else if (jqXHR.status == 500) {

                alert('Internal Server Error [500].');

            } else if (exception === 'parsererror') {

                alert('Requested JSON parse failed.');

            } else if (exception === 'timeout') {

                alert('Time out error.');

            } else if (exception === 'abort') {

                alert('Ajax request aborted.');

            } else {

                alert('Uncaught Error.\n' + jqXHR.responseText);

            }

        }

    });

});