When is it time to end a friendship?

I think, when someone has broken your trust. If someone has betrayed you, and you let him/her know how hurt you are, and yet they do it again, then it is time to say goodbye. It doesn't mean you can never see that person again, but the friendship will no longer be as close as it once was. Instead this person will become more of an acquaintance. And I know it is hard, if you have been friends for a long time. But at least take a break. It's possible this person could see their wrongs and change. Then maybe, down the road, you could be friends again.