Disallowing Coupons for Group Pricing Customers?

[dtakle]

zen 1.3.7.1
I want to prevent customers who already have Group Discounts from making use of a Discount Coupon.

Supposing I test for this in ot_coupon.php, is there an easy way to check an order to see if any Group Discounts have been used?
I can code php ok, but I have a lot of trouble understanding zen structure and code. I would greatly appreciate it if someone could post a snippet of code that would test this condition. Or point me to some existing zen code that tests this.

Thanks,
~David

[dtakle]

BTW, I am using the "Group Pricing (per item)" Addon by Dave Simmons

[GG01]

You can check out:

http://www.zen-cart.com/forum/showth...SCOUNT+COUPONS

Hope it helps!