Building a laptop charger?

i do have a adjustable dc power supply(0-30). i do have a proto-board (breadboard) and i do have a cord that can plug into my laptop from the proto-board. the laptop runs on 19v-2.64 amps. i figured simply using ohms law i would get what i need, but no that didn't work, my resistors are just burning up. cant i just build a simple circuit to run the laptop.