Hello. I am having trouble installling the "add customer from admin" addon. I have uploaded all the files as instructed, and have the form to fill out for the customer, but when I hit submit, I get the following error:

Not Found (404)
The requested URL /admin/add_customers.php?action=add_complete was not found on this server.

I really hope someone can help, because this is a very important addon for me since we take a lot of orders over the phone. This will save me from having to create a new account through the store every time, then emailing every customer with their username and password.

if this does not work, is there some way to add them as a customer in my database, but not create an online logon for them so that i could track them but would not have to notify them of the new account?

Thank you very much!