the varrible has not been assigned

I’m trying to cause a fire to switch by pressing E in a specific place but it won’t let me
this is my script:

#pragma strict

var Fire1 : GameObject;
var Fire2 : GameObject;

private var drawGUI = false;


function Update () 
{
	if (drawGUI == true == true && Input.GetKeyDown(KeyCode.E))
	{
		changeFireState();
	}
}

function OnTriggerEnter (theCollider : Collider)
{
	if (theCollider.tag == "Player")
	{
		drawGUI = true;
	}
}

function OnTriggerExit (theCollider : Collider)
{
	if (theCollider.tag == "Player")
	{
		drawGUI = false;
	}
}

function OnGUI () {
    if (drawGUI == true)
    {
		GUI.Box (Rect (Screen.width/2 - 51, 200, 102, 22), "Press E to lit");
	}
}

function changeFireState ()
{
  if (Fire1.active == true)
 {
 	Fire1.SetActiveRecursively(false);
 	Fire2.SetActiveRecursively(true);
 }
 else
 {
 	Fire1.SetActiveRecursively(true);
 	Fire2.SetActiveRecursively(false);
 }
}

if (drawGUI == true == true && Input.GetKeyDown(KeyCode.E))

should read

if (drawGUI && Input.GetKeyDown(KeyCode.E))

First thing you’re gonna want to do is change

if(drawGUI == true == true && Input.GetKeyDown(KeyCode.E))

to

if(drawGUI == true && Input.GetKeyDown(KeyCode.E))

Second of all, are you sure OnTriggerEnter is triggered? If not, make sure one of your gameobjects have a rigidbody attached to it.