Thread: how to limit users selecting multiple categories to post ads into?

how to limit users selecting multiple categories to post ads into?

I have discovered that with WP, my users now have their own dashboard and even though that is all good it also allows them to be able to select as many categories as they want to post their AD into, which is not good!

how do I prevent my users to only be allowed to post in one category for a specific AD but if they select multiple categories how do I force a payment page to come up saying that unless they are willing to pay "X" amount then they are only allowed to display their AD into ONE category?

thanks in advance