The easiest way to do this is to simply enter the url to be downloaded in the field for "User Field Five" for that product in the add a product or edit a product screen of the manager:

 I.E. http://king-cart/instructions.html

 If a key is entered, then an id/password will be appended to the end of the url as shown below where the password is generated from the key. This is a typical entry if the file and download script are both on the KingCart server, and the item is "poem". The key for the password is "testing2".
 I.E. if the following is entered for the User Field 5:

http://king-cart.com/cgi-bin/download.pl?item=poem testing2

 Then the following link will be emailed to the customer when payment is received:

http://king-cart.com/cgi-bin/download.pl?item=poem&id=mdudley-558-1&password=tejTyaVyxFuY

 The "558" is the invoice number, and the "1" means it is the first downloadable item for that invoice.
For this a script MUST be used to check the password and send the file so it cannot be downloaded more than once; and hackers cannot post a url or password to download it.

Once a file has completed downloading, it will be written to a log file by the script so it cannot be downloaded again with that purchase, or the script can be configured to allow multiple downloads for a certain number of days after purchase.

 To tell the cart this item is downloaded and to allow the item to be either downloaded or shipped, the download is handled as an "option". If the download option is selected than the shipping weight is forced to "0".

 This option file for downloading can be used if the item can only be downloaded:

<input type=hidden NAME = "option|1|%%PRODUCT_ID%%" value="[download]">

When a download is called for, there is normally no shipping associated with it. Thus the above link will not charge any shipping normally. If however you are wanting to ship something in addition to the download, and wish to charge shipping, then use the following option file instead:

<input type=hidden NAME = "option|1|%%PRODUCT_ID%%" value="[Download]">

Note the "D" in download is capitalized to force it to charge shipping. As with any product you will likely need to enter a weight in for the shipped portion.

 This is one of your standard option files, that can be selected by entering "download.html" in the options box.
If you want the customer to choose between download and shipping the item, then put "downloadship.html" in the options field for that item. This is a standard option file as well. You can edit it once you have put it in this field.

 This option will appear with the product as shown below: (it is operational)

 This will allow your customer to select if they want to download the item, or have it shipped to them on a disk. The shipping option has a $3.00 adder which automatically gets added to the order if they select it.
On your server you will need to run a cgi script to check the password, prevent re-use of the same password by someone else and, if you have more than one product, send the correct product to the customer.

 The script download.pl will accomplish this for you. Copy the code to the cgi-bin directory on your site. This is normally done by saving it to your hard drive, then uploading it to your webserver. Then in the "User Field Five" for the item(s) to be downloaded, enter:

http://yoururl.com/cgi-bin/download.pl?item=[alias] [password]

 Note that [alias] is a unique id of that item that the script can use to look up the filename of the download, and [password] is the key to be used to generate the password. They should be be alphanumerics, avoid punctuation characters such as apostrophe's. Each item can use their own password. Of course the "yoururl.com" is the domain of your site, and if you have the script in a directory other than cgi-bin, that needs to correspond with the actual directory name.

Important: The password must be a minimum of 8 characters, or the password checking will fail.