Unable to upload images using native rails file upload

I am a rails newbie and am trying to build my first app. I have a jobs
and categories controller and models respectively.

CONTROLLER:

def new
    @job = Job.new
    @catergory = Catergory.all

    respond_to do |format|
      format.html # new.html.erb
      format.xml { render :xml => @job }
    end
  end

#THIS IS A group of 10 RADIO_BUTTONS TO SELECT A CATEGORY FROM. BY
DEFAULT THE FIRST ONE IS SELECTED. !!!!!!!!!!AM STUCK HOW TO WORK
IT!!!!!!!!!!!!maybe a partial???

  <dt><%= f.label "Category" %></dt>
  <% @job.catergory.each do | f | %>
    <dd>
      <%= f.radio_button :name, :id %>
    </dd>
  <% end -%>

# UPLOAD a file for the logo in the controller???
  def upload
    uploaded_io = params[:job][:logo]
      File.open(Rails.root.join('public', 'images',
uploaded_io.original_filename), 'w') do |file|
        file.write(uploaded_io.read)
      end
  end

#VIEW FILE views/jobs/new.html.erb
<dl>
<% form_for (@job, :html => {:multipart => true }) do |f| %>
  <%= f.error_messages %>

<dt><%= f.label "title" %></dt>
      <dd>
    <%= f.text_field :title %>
    <br>
    <span class="hint">"Senior Ruby Developer" or "HTML5 CSS3 Guru"</

  </dd>

yada yada yada...

yada yada yada...

yada yada yada...

    <dt><%= f.label "Name" %></dt>
    <dd>
    <%= f.text_field :company %>
    <br>
    <span class="hint">Example: 'Safarista Design', 'Safrista Jobs' or
'37signals'</span>

  </dd>
</dl>

yada yada yada...

yada yada yada...

yada yada yada...

<%= f.submit 'Step 2: Proceed to preview your ad &rarr;' %>

<% end %>

This is not working. What am i doing wrong?

There was a mistake while pasting

I am a rails newbie and am trying to build my first app. I have a jobs
and categories controller and models respectively.

CONTROLLER:

def new
    @job = Job.new
    @catergory = Catergory.all

    respond_to do |format|
      format.html # new.html.erb
      format.xml { render :xml => @job }
    end
  end

# UPLOAD a file for the logo in the controller???
  def upload
    uploaded_io = params[:job][:logo]
      File.open(Rails.root.join('public', 'images',
uploaded_io.original_filename), 'w') do |file|
        file.write(uploaded_io.read)
      end
  end

#VIEW FILE views/jobs/new.html.erb
<dl>
<% form_for (@job, :html => {:multipart => true }) do |f| %>
  <%= f.error_messages %>

<dt><%= f.label "title" %></dt>
        <dd>
                <%= f.text_field :title %>
                <br>
                <span class="hint">"Senior Ruby Developer" or "HTML5
CSS3 Guru"</

        </dd>

#THIS IS A group of 10 RADIO_BUTTONS TO SELECT A CATEGORY FROM. BY
DEFAULT THE FIRST ONE IS SELECTED. !!!!!!!!!!AM STUCK HOW TO WORK
IT!!!!!!!!!!!!maybe a partial???

        <dt><%= f.label "Category" %></dt>
        <% @job.catergory.each do | f | %>
                <dd>
                        <%= f.radio_button :name, :id %>
                </dd>
        <% end -%>

yada yada yada...

yada yada yada...

yada yada yada...

    <dt><%= f.label "Name" %></dt>
    <dd>
                <%= f.text_field :company %>
                <br>
                <span class="hint">Example: 'Safarista Design',
'Safrista Jobs' or
'37signals'</span>

        </dd>
</dl>

yada yada yada...

yada yada yada...

yada yada yada...

<%= f.submit 'Step 2: Proceed to preview your ad &rarr;' %>

<% end %>

This is not working. What am i doing wrong?

I have 2 models Category and Job. How do I make the user select a
category from a list of radio buttons in the view/jobs/new form. How
do I then associate the job with the selected Category. Please help.

http://visionmasterdesigns.com/tutorial-create-blog-using-ruby-on-rails-2-relationship/2/

Do same as with yours Category and job