I quit whenever I double what I had when I started or, When i lost about 30 percent of what I had when I started. But it is hard to quit so you have ot have real good control over yourself if you are losing and winning sometimes.
I was playing some cash games at absolutpoker.. I had ak and i only had around 5 dollars in limit holdem. the flop came jxa. I raised, her called. The turnm was another x. Then i raised gain and by this time I was all-in. Then the river came another j. He had jk. I was extremely pissed after this one.