rails jquery ajax,Rails and Jquery ajax

I follow this tutorial (except I put gem 'jquery-rails' in my gemfile ).

The problem, if I click to new post, and fill the form and click to create -> ajax don't work, and show method showing the simple post.

my create.js.erb:

$('body').html("

").append("");

create method

def create

@post = Post.new(params[:post])

respond_to do |format|

if @post.save

format.html { redirect_to(@post, :notice => 'asdasd') }

format.js

else

format.html { render :action => "new" }

format.js

end

end

end

_form.html.erb

true) do |f| %>

prohibited this post from being saved: