Well, I don't want to go into deep maths but the chance of creating the same cID is infinitesimal.. so one doesn't have to manage this case graciously. I.e. Just refresh the page or make a soft refresh (clear the models and re-send the data from the db, which isn't huge since that part is already coded for the initial loading). It's not the same as if it had 1/10 chance and you had to be clever to fix it. I mean, even without this problem, it happens from time to time that the best software needs to refresh because of a small bug.