how to destroy camera instatiated from prefab?

Hello!

I want to make a simple script for menu cameras. When I'm pressing Space I want to spawn mainmenucam and destroy introcam and it kinda works,but it does not destroys the introcam

Here's my code so far

 var introcam : GameObject;
 var mainmenucam : GameObject;
 
 function Start () {
      
      Instantiate(introcam); 
 }
 
 function Update () {
 
  if (Input.GetKeyDown ("space")) 
  {
  Destroy(GameObject.Find("introcam"));
  
      Instantiate(mainmenucam);
  }
 
  if (Input.GetKeyDown ("up")) 
  {
  Destroy(GameObject.Find("mainmenucam"));
 
      Instantiate(introcam);
  }
 
 }
 
 

How can I fix this?