gistfile1.js

$(function() {
    (function() {
        $('form').submit(function() {
            $.ajax({
                url: '/app_dev.php/users/510a702aa3d0b4f0c9dbf10b/edit',
                data: $('form').serialize(),
                type: 'POST',
                dataType: 'json',
                success: function(data, textStatus, jqXHR ) {
                    if (data.status == 'invalid') {
                        $('form img').prop('src', data.img);
                        $('img').insertAfter('error!');
                    }
                    else {
                        window.location = data.redirect;
                    }
                },
                error: function(jqXHR, textStatus, errorThrown) {
                }
            });

            return false;
        });
    })();
});