AI Picking New Target After First Target Gets Destroyed

Hi! All I would like to know is how I could make my friendly AI pick a new target after it's original target was destroyed. When it's original target gets destroyed, the friendly AI's target comes up as "missing." I have been trying to target a new target (also the enemy) with gameobject.findwithtag but it's not working. So far all I have is when the enemy dies, it tells the friendly AIs that it's destroyed and they need to find a new target. Thanks!! P.S. - I'm trying to target the same enemy kind but different gameobject. Update with code of my friendly unit :P)

 var target : Transform; //the enemy's target
 var moveSpeed = 4; //move speed
 var rotationSpeed = 3; //speed of turning
 
 private var nextFireTime : float;
 var fireDelay : float;
 
 public var chasing = false; //Player
 var shootSound : AudioClip; 
 var Dead : GameObject;
 var hitPoints : int = 200;
 var Bullet : GameObject;
 var hitParticles : ParticleEmitter; //Sparks
 var hitParticles2 : ParticleEmitter; //Blood
 var hitParticles3 : ParticleEmitter; //Dirt
 var force = 50.0;
 var range = 150.0;
 var decalHitWall : GameObject;
 var BulletTracer : GameObject;
 var SpawnPoint : GameObject;
 private var floatInFrontOfWall : float = 0.001;
 var damagechest = Random.Range(10.0, 15.0);
 var hitdamage = Random.Range(70.0, 80.0);
 var myTransform : Transform; //current transform data of this enemy
 public var Fire : int = 0;
 var hitTime : float;
 private var nextHitTime : float;
 public var AtPosition = false;
 public var JustGotShot = false;
 public var targetdestroyed : boolean;
 
 function Awake()
 {
     myTransform = transform; //cache transform data for easy access/preformance 
           
     }
 
 function Start()
 {
       target = GameObject.FindWithTag("Enemy").transform;
     }
 
 function Update () {
 if (hitPoints <= 0)
    {
       Destroy(gameObject);
       Instantiate(Dead, transform.position, Quaternion.identity);
       GameObject.Find("LZ").GetComponent(PointManager).points -= 100;
    }
    
    // check distance to target every frame:
 var distance = (target.position - myTransform.position).magnitude;
    
     if(JustGotShot == true) {
     GetComponent(FriendlyDodge).GetHim = true;
    }
 
     if (chasing) {
         //rotate to look at the player
         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 (distance <= 10 && Fire == 1) {
        moveSpeed = -1;    
 }
  if (distance >= 11) {
        moveSpeed = 4;    
 }
  if(distance <= 4) {
   GetComponent(FriendlyRaycast).noMelee = 1;
   Fire = 0;
   if(Time.time > nextHitTime) {
   hitdamage = Random.Range(70.0, 80.0);
   GameObject.FindWithTag("Enemy").GetComponent(Enemy).TakeDamage(hitdamage);
   nextHitTime = Time.time + hitTime; 
   }
 }
  if(distance >= 5) {
  GetComponent(FriendlyRaycast).noMelee = 0;
 }
 }
 if(chasing == false && GetComponent(FriendlyDodge).Attack == true && AtPosition == false) {
         distance3 = (GetComponent(FriendlyRaycast).LastPlayerPosition - myTransform.position).magnitude;
         myTransform.rotation = Quaternion.Slerp(myTransform.rotation,
         Quaternion.LookRotation(GetComponent(FriendlyRaycast).LastPlayerPosition - myTransform.position), rotationSpeed*Time.deltaTime);
         myTransform.position += myTransform.forward * moveSpeed * Time.deltaTime;;
         if(distance3 <= 0.5) { 
         AtPosition = true;
         chasing = true;
         GetComponent(FriendlyDodge).Attack = true;
         }
         }
         if(GetComponent(FriendlyRaycast).CantSee == true && AtPosition == true) {
         chasing = false;
         GetComponent(FriendlyDodge).Attack = false;
         }
         
         
 if(Time.time > nextFireTime && Fire == 1) {
         
         FireOneShot();        
         nextFireTime = Time.time + fireDelay; 
         audio.PlayOneShot(shootSound); 
         } 
         if(targetdestroyed == true) {
         
         FindNewTarget();    
         }
         }
         function FindNewTarget() {
         
         target = GameObject.FindWithTag("Enemy").transform;
         }