Topic awaiting preservation: Auto Refresh or something like it.

One of the stores that I am using, running OsC issues a PIN number at the checkout_success level that is created from another company's website. The problem is that this pin number needs to be unique for each product downloaded. If you clear your cache before ordering each product no problem, but for many people this will not happen. Is there a bit of code that can be placed in my shopping cart that will clear the cache of the user so their issued PIN will always be unique?

http://www.mnot.net/cache_docs/ ?