I just installed the demo of your product and got it up and running in no time. I searched high and low for a decent login script and thank God I found yours.
I looked all over trying to find a simple cgi script. I found that FileChucker was by far the best. If you have issues with your hosting service's php.ini max upload size then this is the way to go. Looking forward to future enhancements.
Do you know how rare it is to have a "canned" shopping cart that can easily do complex pricing options on a single item? Basically, they don't exist! I have looked. Everywhere! And the few that might even come close to CornerStore's functionality cost a fortune!