maximum checkout items

I had some trouble with with the 'Ubercart Min/Max Order Quantity' module.

To fit my needs I updated a small module from D5 to D6 that sets max items for your cart to checkout.
e.g i want customers to be able to buy a max of 10 products per order. I set max items to 10.
There is a cutom error message available.

The bad:
variables(amount and error text) are only editable in the module itself, so for a multisite you need to place module into he following folder
sites/all/yoursite/modules/