The screws should be two different colors, one silver and one brass. The white wire goes on the silver one and the black on the brass. As unix-guy pointed out it really shouldn't make a difference but swapping the wires will reverse the phase (polarity) of the power which could introduce some humming.
Power cords are really cheap. why do you have one without molded ends? anyone that sells computer or electronic items should have them for $5-10 bucks