free download of document

I want to have a download for customers to access a catalogue - for free.
I have created a product: as document-general
added attributes - product option is 'download' as a radio button
option value is 'ripfile'
put into attributes zencarts zipped pdf file name from download file 'sample_pdf.zip'

Got a green light! I go on to the site and have a 'Please Choose download (radio button) zipfile on this product page

There is no where for the customer to actually download from.....
I don't need different download types choice, just want to have the customer be able to download a pdf file at will. Shouldn't be too hard........hmmmmmm.......I am new at this.....
I have /pub at 777
redirect is true
freecharge set to 3
???????
Please help....Thanks

Would be easier to link to file for download via html code..
if not, zencart downloads are normally only available
when someone has purchased, free or not, and then link
to download appears via their account page..

Thanks,
I can do that - just would have preferred it in the password protected section of the ZC.
But...if I kept it in the product document general section.....How would the customer add it to their cart, at this stage - there is no button to add to cart...or download...... anything..???
:unsure:

Url of your site not given so unable to see current setup re this product/document..
however demo of how should be implemented is shown at
http://www.zen-cart.net/demo/index.php?main_page=document_product_info&cPath=63&products_id=171