Rails远程表单回调ajax：加载不会触发，其他人则执行

Here's my code:

这是我的代码：

$('#fb_login_form').bind('ajax:loading', function() {alert("loading!");});
.bind('ajax:success', function(data, status, xhr) {alert("success!");})
.bind('ajax:failure', function(xhr, status, error) {alert("failure!");})
.bind('ajax:complete', function() {alert("complete!");});
$('#fb_login_form')