Switching Between Cameras JavaScript

I have a school assignment I am doing and I am trying to switch between two different cameras but it won't work for me.

My cameras are: 1. MainCamera 2. OtherCamera

My script is:

 var camera1:ThirdPersonCamera;
 var camera2:OtherCamera;
  
 function Start()
 {
 camera1.enabled = true;
 camera2.enabled = false;
 }
  
 function Update()
 {
 if (Input.GetKeyDown("b"))
 {
 camera2.enabled = true;
 camera1.enabled = false;
 }
  
 else if (Input.GetKeyDown("n"))
 {
 camera2.enabled = false;
 camera1.enabled = true;
 }
 }

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[2]: /storage/temp/27659-screen+shot+2014-06-13+at+4.07.43+pm.png