Raycasting help, enemy damage

Hello again, i have a question about raycasting and enemy damage. Here is my script.what i want to happen is if i shoot a raycast at an object tagged "Enemy" then health is taken away.

 var health = 150
 var target : Transform;
 var moveSpeed = 3;
 var rotationSpeed = 3;
 var myTransform : Transform;
 
 function Awake()
 {
     myTransform = transform;
 }
 
 function Start()
 {
     health = 150;
     target = GameObject.FindWithTag("Player").transform;
 }
 
 function Update(){
     transform.LookAt(Vector3(target.position.x, transform.position.y, target.position.z));
     
     myTransform.Translate(Vector3.forward * moveSpeed * Time.deltaTime);
 }
 
         if( // stuff here