script not working on second character

so i have a script here it works fine but then it doesnt work on the second character even thou they are copys of each other anybody know what im doing wrong

 var waypoint : Transform[];

static var speed : float = 5; private var currentWaypoint : int;

function Update () {

 var Enemy = GameObject.FindWithTag ("Enemy");
 
 
     if ( Vector3.Distance(Enemy.transform.position, transform.position ) < 3) {
     transform.LookAt(Enemy.transform);
     print("suck mun dee");
     rigidbody.constraints = RigidbodyConstraints.FreezePositionX |RigidbodyConstraints.FreezePositionZ|RigidbodyConstraints.FreezePositionY;

 }
 
  if(currentWaypoint < waypoint.length)
     {
     
         var target : Vector3 = waypoint[currentWaypoint].position;
         var moveDirection : Vector3 = target - transform.position;
         var velocity = rigidbody.velocity;

         if(moveDirection.magnitude < 1)
         {
             currentWaypoint++;
         }
         else
         {
             velocity = moveDirection.normalized*speed;
         }
                      rigidbody.velocity = velocity;
     }
    
 }