- <a href="{% url download_zip_mp3 book.fileid %}">MP3</a>{% if have_oggs %},
- <a href="{% url download_zip_ogg book.fileid %}">Ogg Vorbis</a>{% endif %}.
+ <a href="{% url download_zip_mp3 book.slug %}">MP3</a>{% if have_oggs %},
+ <a href="{% url download_zip_ogg book.slug %}">Ogg Vorbis</a>{% endif %}.