AI for enemy characters

recently i purchased few characters for my game imported those characters and added animation files and added AI script to that character every thing works fine but the character is turning around as shown in the video(http://www.youtube.com/watch?v=YLQ-a8h5_iE)

this is the script attached pls help me

var speed = 3.0; var rotationSpeed = 5.0; var shootRange = 15.0; var attackRange = 30.0; var shootAngle = 4.0; var dontComeCloserRange = 5.0; var delayShootTime = 0.35; var pickNextWaypointDistance = 2.0; var target : Transform;

private var lastShot = -10.0;

// Make sure there is always a character controller @script RequireComponent (CharacterController)

function Start () { // Auto setup player as target through tags if (target == null && GameObject.FindWithTag("Player")) target = GameObject.FindWithTag("Player").transform;

Patrol();

}

function Patrol () { var curWayPoint = AutoWayPoint.FindClosest(transform.position); while (true) { var waypointPosition = curWayPoint.transform.position; // Are we close to a waypoint? -> pick the next one! if (Vector3.Distance(waypointPosition, transform.position) < pickNextWaypointDistance) curWayPoint = PickNextWaypoint (curWayPoint);

// Attack the player and wait until // - player is killed // - player is out of sight if (CanSeeTarget ()) yield StartCoroutine("AttackPlayer");

 // Move towards our target
 MoveTowards(waypointPosition);

 yield;

}

}

function CanSeeTarget () : boolean { if (Vector3.Distance(transform.position, target.position) > attackRange) return false;

var hit : RaycastHit; if (Physics.Linecast (transform.position, target.position, hit)) return hit.transform == target;

return false;

}

function Shoot () { // Start shoot animation animation.CrossFade("shoot", 0.3);

// Wait until half the animation has played yield WaitForSeconds(delayShootTime);

// Wait for the rest of the animation to finish yield WaitForSeconds(animation["shoot"].length - delayShootTime);

}

function AttackPlayer () { var lastVisiblePlayerPosition = target.position; while (true) { if (CanSeeTarget ()) { // Target is dead - stop hunting if (target == null) return;

// Target is too far away - give up var distance = Vector3.Distance(transform.position, target.position); if (distance > shootRange * 3) return;

     lastVisiblePlayerPosition = target.position;
     if (distance > dontComeCloserRange)
         MoveTowards (lastVisiblePlayerPosition);
     else
         RotateTowards(lastVisiblePlayerPosition);

     var forward = transform.TransformDirection(Vector3.forward);
     var targetDirection = lastVisiblePlayerPosition - transform.position;
     targetDirection.y = 0;

     var angle = Vector3.Angle(targetDirection, forward);

     // Start shooting if close and play is in sight
     if (distance < shootRange && angle < shootAngle)
         yield StartCoroutine("Shoot");
 } else {
     yield StartCoroutine("SearchPlayer", lastVisiblePlayerPosition);
     // Player not visible anymore - stop attacking
     if (!CanSeeTarget ())
         return;
 }

 yield;

}

}

function SearchPlayer (position : Vector3) { // Run towards the player but after 3 seconds timeout and go back to Patroling var timeout = 3.0; while (timeout > 0.0) { MoveTowards(position);

// We found the player if (CanSeeTarget ()) return;

 timeout -= Time.deltaTime;
 yield;

}

}

function RotateTowards (position : Vector3) { SendMessage("SetSpeed", 0.0);

var direction = position - transform.position; direction.y = 0; if (direction.magnitude < 0.1) return;

// Rotate towards the target transform.rotation = Quaternion.Slerp (transform.rotation, Quaternion.LookRotation(direction), rotationSpeed * Time.deltaTime); transform.eulerAngles = Vector3(0, transform.eulerAngles.y, 0);

}

function MoveTowards (position : Vector3) { var direction = position - transform.position; direction.y = 0; if (direction.magnitude < 0.5) { SendMessage("SetSpeed", 0.0); return; }

// Rotate towards the target transform.rotation = Quaternion.Slerp (transform.rotation, Quaternion.LookRotation(direction), rotationSpeed * Time.deltaTime); transform.eulerAngles = Vector3(0, transform.eulerAngles.y, 0);

SendMessage("SetSpeed", speed * speedModifier, SendMessageOptions.DontRequireReceiver);

}

function PickNextWaypoint (currentWaypoint : AutoWayPoint) { // We want to find the waypoint where the character has to turn the least

// The direction in which we are walking var forward = transform.TransformDirection(Vector3.forward);

return best;

}