[Rails] Processing ajax form

I'm learning rails, while doing my app.
So this is just the tip of the ice berg and I foresee many more questions
in future.

I have the following setup.
Basically, on clicking the login button, a ajax request is sent, and the
json response "message":"fail" is returned.

My question is, how do I get the response in the success callback for
processing?
Here's what I have at the moment.

index.html.erb

<h2>Log in</h2>
<%= form_for @user, :remote => true, :url => { :action => "login", :controller => "users" }, :html => { :class => "login" } do |f| %>
<%= label_tag(:password, "Password") %>
<%= f.text_field :password %>
<%= f.submit "Login" %>
<% end %>

home.js.coffee

$ ->
$('form').bind 'ajax:success', (result) -> console.log(result)

Output of console log

jQuery.Event {type: "ajax:success", timeStamp: 1353575112551, jQuery18209272595844231546: true, isTrigger: true, exclusive: undefined…}

I was actually expecting the console log output to be something like result[{
"message" : "fail"}]?