revise enemy code to player code

i want to remake this script.. like when they enter the range of "Chase Treshold" the object will become the target.. its like a loop in the "Chase Treshold", i need help.. i've tried many ways until i broke the whole codes and thank god i still have the working codes

heres the code:

 var target : Transform; //the enemy's target
 
 var moveSpeed = 3; //move speed
 
 var rotationSpeed = 3; //speed of turning
 
 var attackThreshold = 1.5; // distance within which to attack
 
 var chaseThreshold = 10; // distance within which to start chasing
 
 var giveUpThreshold = 20; // distance beyond which AI gives up
 
 var attackRepeatTime = 1; // delay between attacks when within range
 
 private var chasing = false;
 
 public var attackTime : float;
 
 var myTransform : Transform; //current transform data of this enemy
 
 
 
 
 function Awake()
 
 {
 
 myTransform = transform; //cache transform data for easy access/preformance 
 
 }
 
 function Start()
 
 {
 
  if (target == null && GameObject.FindWithTag("Player"))
 
    target = GameObject.FindWithTag("Player").transform;
   
 
 
     
 }
 
 
 
 
 function Update () {
 
 // check distance to target every frame:
 
 var distance = (target.position - myTransform.position).magnitude;
 
 
 
 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;
       animation.Play("Creep");
     
     
 
 
 
     // give up, if too far away from target:
 
     if (distance > giveUpThreshold) {
 
         chasing = false;
 
     }
 
 
 
     // attack, if close enough, and if time is OK:
 
     if (distance < attackThreshold && Time.time > attackRepeatTime) {
 
           animation.Play("Shew");
             
 
                target.SendMessage("ApplyDamage",10);
                 
         // Attack! (call whatever attack function you like here)
     if (attackTime != attackRepeatTime) {
         target.SendMessage("ApplyDamage",0);
         }
         }
 
     if (distance < attackThreshold) {
 
     moveSpeed=1;
 
     //stop when close enough
 
 }
 
 
 
         attackTime = Time.time+ attackRepeatTime;
 
     }
 
 
 
   else {
 
     // not currently chasing.
 
    animation.Play("Creep");
 
     // start chasing if target comes close enough
 
     if (distance < chaseThreshold) {
 
         chasing = true;
 
     }
 
 }
 }
 
 function OnTriggerEnter (other: Collider) {
 
 if (other.gameObject.CompareTag("Bullet")){
 
 chaseThreshold=100000000;
 
 }
 
 }