Zombie script

I am trying to make a zombie game. I keep on getting compiler err. can any one fix it?

here it is

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;
private var attackTime = Time.time;

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("Player").transform; //target the player
}

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;
        // 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) {
            target.SendMessage("ApplyDamage",10);
            // Attack! (call whatever attack function you like here)
        }
        if (distance < attackThreshold) {
            moveSpeed=0;
            //stop when close enough
        }
        attackTime = Time.time+ attackRepeatTime;
    } else {
        // not currently chasing.
        // start chasing if target comes close enough
        if (distance < chaseThreshold) {
            chasing = true;
        }
    }
}

function OnTriggerEnter (other: Collider) {
    if (other.gameObject.CompareTag("Bullet")){
        chaseThreshold=100000000;
    }
}

a) Asking someone to write some script for you