Enemy Jump AI Problem

I built this game http://youtu.be/JNQ7EcEALY0

But my enemy is not jumping properly. Please Help Code

public class enemyaiscript : MonoBehaviour {

     public float speed = 8.58f;
 public float jetPackSpeed = 0.9f;
 public float jumpSpeed = 8f;
 public float gravity = 10f;
 
 private Transform _Player; 
 private CharacterController character;
 private Transform tr;
 private float vSpeed = 0f;
 private bool jump = false;
 
 void Start ()
 {
     _Player = GameObject.FindGameObjectWithTag("Player").transform;
     character = GetComponent<CharacterController>();
     tr = transform;
 }
 
 void Update ()
 {    
     Vector3 chaseDir = _Player.position - tr.position;
     float distance = chaseDir.magnitude;  
     if (distance <= 2) 
     {
                     Debug.Log ("Attacking Player");
         Destroy (GameObject.FindGameObjectWithTag("Player"));
         Application.LoadLevel(3);
         return;

             }
      if (character.isGrounded)
     { 
         Debug.Log("Inside IF");
         vSpeed = 0;  
             if (jump)
         {   
             Debug.Log("Inside Jump");
                 vSpeed = jumpSpeed; 
                 jump = false; 
             }
         } 
         else 
         if (!Physics.Raycast(tr.position, -tr.up, 0.3f)){ 
             vSpeed = jetPackSpeed;  
         }
         vSpeed =vSpeed - (gravity * Time.deltaTime);

         chaseDir = chaseDir.normalized * speed;
         chaseDir.y += vSpeed; 
         character.Move(chaseDir * Time.deltaTime);
     }

 
 void OnControllerColliderHit(ControllerColliderHit hit){
         if (Mathf.Abs(hit.normal.y) < 0.5){
         jump = true; 
     }
 }

}