odds of calculating a flush/straight.

[icedevil2002]

I was wondering if anyone knew the way of calculating the odds of hitting a flush/straight out of a draw by the river i know that a flush has about 9 outs and an open ended straight has 8 outs but then when you are talking about a flush draw you should discount 2 outs when talking about 10 person game. So if you flop a flush draw or an open ended straight draw. whats the are odds that you will hit either one by the river