Melee combat cooldown with animations

Hello, I've this problem, I am using the script from the tutorials and adjusted it to fit with my model's attack action. But now whenever I click the attack button nothing even happens. the major problem was that the animation doesn't occur due to cooldown. but now nothing happens at all

 using UnityEngine;
 using System.Collections;
 
 public class PlayerAttack : MonoBehaviour {
     public GameObject target;
     public float attackcooldown;
     public float attacktimer;
 
     // Use this for initialization
     void Start () {
         attackcooldown=2.0f;
         attacktimer=0;
     }
     
     // Update is called once per frame
 
     void Update() {
         if (attacktimer > 0)
                         attacktimer -= Time.deltaTime;
         if (attacktimer < 0)
                         attacktimer = 0;
         if (Input.GetKey(KeyCode.F) && !animation.isPlaying) 
         {
             if(attacktimer == 0)
             {
             animation.Play("attack 1");
             AttackingEnemy();
             attacktimer = attackcooldown;
             }
         }
         if (Input.GetKey(KeyCode.X)) 
         {
             animation.Play("attack 2");
             
         }
         if (Input.GetKey(KeyCode.Z)) 
         {
             animation.Play("attack 3");
             
         }
 }
     private void    AttackingEnemy(){
         float distance = Vector3.Distance (target.transform.position, transform.position);
         Vector3 dir = (target.transform.position - transform.position).normalized;
         float direction = Vector3.Dot (dir, transform.forward);
         if (distance < 2.5) {
                         if (direction > 0) {
                                 EnemyHealth troll = (EnemyHealth)target.GetComponent ("EnemyHealth");
                                 troll.adjusting (-10);
                         }
                 }
     }
 
 }