targetting dont work

 using UnityEngine;
 using System.Collections;

 public class NewBehaviourScript : MonoBehaviour {
 public playerTarget Transform;
 public pa PlayerAttack = GetComponent("PlayerAttack");
 //empty RaycastHit object which raycast puts the hit details into
 public hit RaycastHit;
 //ray shooting out of the camera from where the mouse is
 public ray Ray = Camera.main.ScreenPointToRay(Input.mousePosition);
 
 void Update() {
 
 //check if the left mouse has been pressed down this frame
 if (Input.GetMouseButtonUp(0)) {
 
         
         
     if (Physics.Raycast(ray, hit)){

     if (hit.collider.gameObject.CompareTag("Enemy")) {
     
     //print out the name if the raycast hits something

         Debug.Log(hit.collider.name);

         playerTarget = hit.collider.transform;

         Debug.Log("PlayerTarget Successfully changed");

         pa.target = playerTarget;

     }
     else{
        
         Debug.Log(hit.collider.name + " no tag");
             }
         }
     }
 }

}

it dont work so pls help

im work in c# not java scipt