Lighting, Light Fixtures, Ceiling and Exhaust Fans - floor lamp wiring question

I am in the process of replacing the socket/switch assembly for a 3-way floor lamp. I successfully removed the old socket/switch assembly and the two wires are exposed and now I can't figure out to which posts of the new socket/swich each of these wires should be connected. Does it matter? Is there an easy way to determine this? I don't want to short out the place by taking the 50/50 guess. Any help would be greatly appreciated. Many thanks.

If you get it right, the shell of the socket will measure zero volts to ground and the button at the bottom of the socket will measure 120 volts to ground. If you get it backwards, you'll get the opposite readings.