C# Script Not Working? (AdvancedAI)

Here's the script:

using UnityEngine; using System.Collections;

public class AdvancedAI : MonoBehaviour { public float Lives = 100; private GameObject player; public float speed = 2.0f; private int Smart = 0; public float Gravity = 9.81f; public float RotationSpeed = 40; public float DeathTime = 5; public CharacterController cc; enum State { Idle, Find, Attack, Death, End, } private State state; // Use this for initialization void Start () { state = AdvancedAI.State.Idle; StartCoroutine(); } IEnumerator () { while (true) { switch (state) { case State.Idle: Idle(); break; case State.Attack: Attack(); break; case State.Find: Find(); break; case State.Death: Death(); break; case State.End: End(); break; } yield return null; }

 }
 
 void Idle () {
     if (player == null) {
         state = AdvancedAI.State.Find;
     }
     else {
         state = AdvancedAI.State.Attack;
         cc.Move(transform.TransformDirection(-Vector3.up * Gravity * Time.deltaTime));
         
     }
 }
 void Attack () {
     if (Lives<=0) {
         state = AdvancedAI.State.Death;
     }
     else {
         if(cc.isGrouded==false) {
         Idle();
         }
         animation["InjuredWalk"].enabled = true;
         animation["InjuredWalk"].normalizedSpeed = Speed;
         Vector3 currentPos = player.transform.position - transform.position;
         Quaternion rot = Quaternion.LookRotation(currentPos);
         cc.Move(transform.TransformDirection(Vector3.forward * Speed * Time.deltaTime));
         transform.rotation = rot;
     }
 }
 void Find() {
     animation["InjuredWalk"].warpMode = WarpMode.Loop;
     animation["InjuredWalk"].enabled = false;
     player = GameObject.FindGameObjectWithTag("Player");
     state = AdvancedAI.State.Idle;
 }
 void Death () {
     Lives = 0;
     Destroy(cc);
     animation["InjuredWalk"].enabled = false;
     //Destroy (gameObject)
     state = AdvancedAI.State.End;
     
 }
 void End () {
 
 }

}

Any clue why it is not working?