def sanitize_html(post)
    return nil if post.body.nil?
    html = post.body.gsub(/^\s*<\!\[CDATA\[/,'')
    document = Hpricot(html, :fixup_tags=>true)
    document.search('script,style,link').remove
    document.search('a,img').each do |osi|
      [:href,:src].each do |attr_name|
        next if osi[attr_name].nil?
        url = osi[attr_name].lstrip
        next if url.match(/^(\s|%20)*(f|ht)tps?:\/\//)
        if post.feed
          osi[attr_name] = begin
            URI.join(post.feed.link, url).to_s
          rescue
            'http://'
          end
        end
      end
    end
    #plushs "S"
    document.to_s
  end