Problem in Edit row in plugin

Rails
1

Hi
I´m new in ruby on rails. I´ve written a plugin in redmine. And add this
plugin to projects tab. I need to show something in that new tab, and
edit
the data.
But now, I have 2 problems:

  1. In the new tab, when I click on the Edit link, the edit page open in
    the
    new page out of projects tab.
  2. In the new page, data get from database correctly and show correctly,
    but when I want to update data, show the error: Page not found

here is my code:

/config/routes.rb :

get 'accounts', :to => 'accounts#index'
post 'post/:id/edit', :to => 'accounts#edit'
post 'post/:id/update', :to => 'accounts#update'

/app/controller/accounts_controller.rb:

class AccountsController < ApplicationController
    unloadable

    def index
        @project = Project.find(params[:project_id])
        @accounts = Account.find(:all)
    end

    def edit
        @account = Account.find(params[:id])
    end

    def update
        @account = Account.find(params[:id])
        if @account.update_attributes(params[:account])
           redirect_to :action => 'edit', :id => @account
        else
           redirect_to :action => 'edit', :id => @account
        end
    end

end

/app/views/accounts/index.html.erb:

<h2>AccounstController</h2>
<% @accounst.each do |account| %>
<table border=1px>
<% if account.project.to_s == @project.to_s then %>
<% @id = account.id %>
<tr>
<td display=inline-block>Project name</td>
<td><%= account.project %></td>
</tr>
<tr>
<td display=inline-block>Cost</td>
<td><%= account.cost %></td>
</tr>
<tr>
<td display=inline-block>Income</td>
<td><%= account.income %></td>
</tr>
<tr>
<td display=inline-block>Factor</td>
<td><%= account.factor%></td>
</tr>
<% end %>
</table>
<% end %>
<%= link_to "Edit", {:action => 'edit', :id => @id } %>

/app/views/accounts/edit.html.erb:

<h1>Editing account </h1>
<%= form_tag :action => 'update', :id => @account do %>

<p><label for="account_cost">Cost</label>:
<%= text_field 'account', 'cost' %></p>

<p><label for="account_factor">Factor</label>:
<%= text_field 'account', 'factor' %></p>

<p><label for="account_income">Income</label>:
<%= text_field 'account', 'income' %></p>

<%= submit_tag "save changes" %>
<% end %>
<%= link_to 'Back', {:action => 'index'} %>

Can anyone help me please?