Turning lights on or off with only 1 button

I have script that have to turn lights on and off only with 1 button, but i am recieving lots of mistakes in console. here is script I am using now:

var Light1 : Light;
var Light2 : Light;
var TopLight : Light;

var allFrontLights = (Light1 && Light2 && TopLight);

function Start () {
	allFrontLights.renderer.enabled = false;
}

function Update () {
	if(Input.GetKeyPress("g") && allFrontLights.renderer.enabled = false){
			allFrontLights.renderer.enabled = true;
	}

		if(Input.GetKeyPress("g") && allFrontLights.renderer.enabled = true){
			allFrontLights.renderer.enabled = false;

	}
}

any help will be OK. thanks.
Nick.

var Light1 : Light;
var Light2 : Light;
var TopLight : Light;

var LightsAreOn : boolean;
 
function Start () {
	LightsAreOn = Light1.enabled = Light2.enabled = TopLight.enabled = false;
}
 
function Update () {
		if(Input.GetKeyDown("g")) {
			if (LightsAreOn) {
				LightsAreOn = Light1.enabled = Light2.enabled = TopLight.enabled = false;
			} else {
				LightsAreOn = Light1.enabled = Light2.enabled = TopLight.enabled = true;
			}
		}
}