Willing To Help A Friend

How far would you go to help out a friend? Is there ever a time when you just have to walk away from the friendship? What are those circumstances?

I have almost never pushed a friend away, and in less than a handful of instances have I stopped being friends with someone. I am always a giving person or at least I try to be. I am willing to stand up for my friends in all kinds of situations and have at times been a middle person or peace keeper to help out the situation. In all my time of being, what i hope is good friend to those around me, I sometimes come to the idea that maybe I put up with more than crap than I really should.

Something that I am beginning to realize is that they might put up with more of my antics than I do of theirs. And I do worry sometimes that I use them irresponsibly. I am not really sure how you would use someone irresponsibly but I worry no matter what that I may have or be doing this. Friends have always been a bit of a mystery for me I guess. I know that doesn't give me a right to treat my friends badly, and for the most part I can't really think of a time that I have done that, though I am human and I am sure there are instances. But I come back to the ultimate question, when is it too far for them to carry me, cover for me, hold me up, or have my back? And vice versus? Is there ever a time when you should walk away from a friend or maybe just not be such good friends?