laravel-errors.js

$.ajax({
        method: POST,
        url: my.app.dev/users/1,
        data: { name: "Matt"}
    })
    .done(function () {
            // whatever you normally do here
    })
    .fail(function (res) {
        if (res.status !== 422) {
            // some other error. Just render a popup or something.
            alert('There was an error saving your work.  Maybe try again?');
            return;
        }
        // otherwise you can parse the response text and get the errors.
        var errors = JSON.parse(res.responseText);
        // First clear out any existing errors.
        $('.my-class form').find('.help-block').text('');
        for (var name in errors) {
            // First find the input element that matches this error
            var $input = $('.my-class form')
                    .find('[name=' + name + ']')
                    .first();
            // Set the has-error class for bootstrap
            $input.parents('.form-group').addClass('has-error');
            // Render the error message in the .help-block div.
            $input.parents('.form-group').find('.help-block').text(errors[name]);
        }
    });