Uploading pdf

I am trying to upload the pdf using file io operations, i can select the
file but when i click on the upload button it is not uploading the file
here is my model

class DataFile < ActiveRecord::Base
    def self.Save(upload)
      name = upload['datafile'].original_filename
      directory = "public/data"
      # create the file path
      path = File.join(directory, name)
      # write the file
      upload_file = File.new(upload['datafile'], 'r').read
      File.open(path, 'w') {|f| f.write(upload_file) }

      image = Magick::ImageList.new('path.pdf')
      images = Dir['public/data/*.jpg']
      imglist = Magick::ImageList.new
      imglist.read(*images)
      imglist.write('name.pdf')
    end
  end

here is my controller

class UploadController < ApplicationController
  def index
    render :file => 'app\views\upload\uploadfile.html.erb'
  end
  def uploadFile
    DataFile.Save(params[:upload])
    render :text => "File has been uploaded successfully"
  end
end

here is my view

<h1>File Upload</h1>
<%= form_tag :url=>{:controller=>"upload",:action =>
'uploadFile'},:html=>{:multipart => true, :remote => true} do |f|%>
<p><label for='upload_file'>Select File</label> :
  <%= file_field 'upload', 'datafile' %></p>
  <%= submit_tag('Upload')%>
<% end%>