It's probably around here somewhere, haven't really bumped into exactly what i'm looking for but here's the question - what do you usually bet in relation to the pot if you put your opp on a flush or straight draw...

ex: pot is 200, your guessing your opp. is on a flush draw, you obv. dont want to chase him away, but what is the right amount to be so he can't call profitably. 1/2, 3/4, the pot (200) ?