HowTo: Hooking up 2 powersources to 1 device with switch

OK, if you don't understand what i mean, this is what my task was. Have my indiglo shift knob come on when my parking lights were turned on, but if i wanted to turn it off while the parking lights were on, i could. I also wanted to be able to turn on the indiglo shift knob if the parking lights were not on. Please don't say just wire and inline switch cause i didn't want that! Well here is how you do it.