Randomizate bullets help

How can i randomizate the bullets in this script ?

using UnityEngine; using System.Collections;

public class EnemyAAi : MonoBehaviour { public Transform target; private float speed = 0; public float normalSpeed = 0; public float maxSpeed = 0; public float rotateSpeed = 0;

 public float lookAtDistance = 80;
 public float attackRange = 40;
 
 
 private Transform myTransform;
 private bool moveForward = false;
 
 public Rigidbody bullet;
 public float bulletSpeed = 0;
 public AudioClip laserSound;
 public Transform muzzle;
 
 public float attackTimer = 1;
 private float timer = 0;
 
 // Use this for initialization
 void Start () 
 {
     myTransform = transform;
 
 }
 
 // Update is called once per frame
 void Update () 
 {
     //40 to attack
     //80 to look
     float distance = Vector3.Distance(target.position, myTransform.position);
     
     
     
     if(distance < lookAtDistance)
     {
         LookAtTarget();
         speed = maxSpeed;
         moveForward = true;
         
         
         if(distance <= attackRange)
         {
             moveForward = false;
             //attack code
             TimeStuff();
         }
         
         
     }
     else
     {
         moveForward = false;
     }
     
     


     //this is for making shure the ship moves and stops
     if(moveForward)
     {
         MoveToTarget();
     }
     else
     {
         return;
     }
 
     

     
     
     
 }
 
 
 //move towards player
 private void MoveToTarget()
 {
     rigidbody.AddForce(myTransform.forward * speed);    
     
 }
 //look at player
 private void LookAtTarget()
 {
     //myTransform.LookAt(target);
     Quaternion rotation = Quaternion.LookRotation(target.position - myTransform.position);
     myTransform.rotation = Quaternion.Slerp(myTransform.rotation, rotation, rotateSpeed * Time.deltaTime);
             
 }
 
 
 private void ShootBullet()
 {
     Rigidbody clone;
     clone = Instantiate(bullet, muzzle.position,muzzle.rotation) as Rigidbody;
     clone.velocity = transform.forward * 100;
     clone.transform.parent = transform;
     
     
     
     
     timer = attackTimer;
     
     
 }
 
 
 private void TimeStuff()
 {
     //making shure timer is doing what is supposed to do
     if(timer <= 0)
     {
         timer = 0;
     }
     
     if(timer > 0)
     {
         timer -= Time.deltaTime;
     }
     
     if(timer == 0)
     {
         ShootBullet();
     }
     

 }
 

public float health=100; //the health variable. public float damage=10; //damage amount. public void hit() { health-= damage; if (health < 0) { }

} }