Detect if Transform is destroyed

I'm making a script for a turret that aims at the object and fires at it when inrange = true, but the gun just keeps firing after the object is destroyed.

AIM SCRIPT

 var target : Transform; //the enemy's target
 var tarpos : Vector3;
 var moveSpeed = 50; //move speed
 var rotationSpeed = 3; //speed of turning
 var thispos : Vector3;
 var inrange = false;
  
 var myTransform : Transform; //current transform data of this enemy
  
 function Awake()
 {
      myTransform = transform; //cache transform data for easy access/preformance
 }
  
 function Start()
 { 
      target = GameObject.FindWithTag("EnemyLand").transform; //target the player
  
 }
  
 function Update () {
 if(target == null){
 print("working");
     inrange = false;
     }
 tarpos = target.position;
 thispos = transform.position;
 
 
 if(Vector3.Distance (thispos, tarpos) < 25){
             inrange = true;
     myTransform.rotation = Quaternion.Slerp(myTransform.rotation,
     Quaternion.LookRotation(target.position - myTransform.position), rotationSpeed*Time.deltaTime);
                 //move towards the player
     myTransform.position += myTransform.forward * moveSpeed * Time.deltaTime;
     }
     if(Vector3.Distance (thispos, tarpos) > 25){
     inrange = false;
     }
     }

SHOOT SCRIPT

 var bullet : Transform;
 var reloadTime = 0.2;
 var LTAcube : GameObject;
 var canfire = true;
 var muzzle : Transform;
 var on : boolean;
 
 function Update () {
 on = LTAcube.GetComponent("LTAI").inrange;
 if(on == true){
 Debug.Log("On Is True");
 if(canfire == true){
 Debug.Log("CanFire Is True");
 Fire();
 Debug.Log("Sending Fire");
 
 }
 
 }
 
 }
 
 function Fire () {
 Instantiate(muzzle, transform.position, transform.rotation);
 Instantiate(bullet, transform.position, transform.rotation);
 Reload();
 Debug.Log("Sending Reload");
 canfire = false;
 if(on == false){
 canfire = false;
 }
 }
 
 function Reload () {
 yield WaitForSeconds (reloadTime);
 Fire();
 }