NoMethodError in Book

Rails
#1

I got a following error.

NoMethodError in Book#new

Showing /home/amrit/boook/app/views/book/_form.html.erb where line #1
raised:

undefined method `model_name’ for NilClass:Class

The content of _form.html.erb file are:

<%= form_for(@post) do |f| %>
<% if @post.errors.any? %>


<%= pluralize(@post.errors.count, “error”) %> prohibited
this post from being saved:

  <ul>
  <% @post.errors.full_messages.each do |msg| %>
    <li><%= msg %></li>
  <% end %>
  </ul>
</div>

<% end %>

<%= f.label :name %>
<%= f.text_field :name %>
<%= f.label :title %>
<%= f.text_field :title %>
<%= f.label :content %>
<%= f.text_area :content %>
<%= f.submit %>
<% end %>

Any clue?
Thanks