Cargo Light Wiring Question

[xludan]

When I purchased my truck the cargo light was not connected and I'm wondering what the correct wiring scheme is for it. I know the interior dome light uses the orange/white wires which is turned on when the headlight switch is turned and connects the white wire to ground. Is the cargo lamp jumpered off of the dome lamp orange white wires or is there a seperate set of wires run for this? If it is jumpered this would mean that you would have to have the dome lamp turned on to make the cargo lamp work. Is this correct (I've made a diagram of what I'm thinking below)?