Ignition key light question

[BadazzSr20]

hey guys

ok i bought one of them 180sx lights the diffrent color ones that go around the place where u stick ur key in to start the car. anyhow im trying to install it i sreached around and tryed the only thing i found on install. they said to get power form your headlights and ground the other wire. well heres the thing i place it on the headlight wire and grounded it and its on all the time 24/7. i need it so when i turn my headlights on the key ring it light up and then when i turn the lights off the key ring turns off too. how can get go about this where it turns off and on with the headlights.

i can run it to a diffrent soruce but the wire is short and i dont want to make the wire longer so the headlight idea is a good idea just it does turn off it only stays on all the time.

any ideas please feel free to help

thanks much