Need A Combat System.

Hello, I have been trying to get a working combat system for my RPG for a while. I am new to unity and I cannot seem to get one working. I have decided to use SendMessage for the combat and I am really stumped. I have found some scripts on the internet that I am editing but I cannot get them to work the way I want them to. I need this script below to send a message to the enemies target that says damage where it says //attack if close enough. The script below is used by enemies.

 // Chasing And Attacking
 var target : Transform; //the enemy's target
 var moveSpeed = 3; //How fast the enemy is
 var rotationSpeed = 3; // How fast enemy turns
 var attackThreshold = 3; // Attacking Range
 var chaseThreshold = 10; // Enemys sight range
 var giveUpThreshold = 20; //  Distance when enemy gets tired
 var attackRepeatTime = 2000; // How fast the enemys attacks come
 var reciever : GameObject;
 
 private var chasing = false;
 private var attackTime = Time.time;
 
 var myTransform : Transform; //current transform data of this enemy
 
 function Awake()
 {
     myTransform = transform; //cache transform data for easy access/preformance
 }
 
 function Start()
 {
      target = GameObject.FindWithTag("Player").transform; //target the player
      reciever = GameObject.FindWithTag("Player").gameObject; //target the player
 }
 
 function Update () {
 
     // check distance to target every frame:
     var distance = (target.position - myTransform.position).magnitude;
 
     if (chasing) {
 
         //rotate to look at the player
         myTransform.rotation = Quaternion.Slerp(myTransform.rotation,
         Quaternion.LookRotation(target.position - myTransform.position), rotationSpeed*Time.deltaTime);
 
         //move towards the player
         myTransform.position += myTransform.forward * moveSpeed * Time.deltaTime;
 
         // give up, if too far away from target:
         if (distance > giveUpThreshold) {
             chasing = false;
         }
 
         // attack, if close enough, and if time is OK:
         if (distance < attackThreshold && Time.time > attackTime) {
             // Attack! (call whatever attack function you like here)
             attackTime = Time.time + attackRepeatTime;
                      // Replace 5 with whatever damage that enemy deals here
             reciever.gameObject.SendMessage ("Damage", 5.0);
 
         }

Here is the script that is used by the player. I need it to - the players health by the float that came with the message every time its repeated.

 var health = 100;
 
 function Damage(Damage : float){
 health -(Damage);
              }             
    if(health <- 0){
    print("Game Over");
    health = 0;
    Destroy (gameObject);  
 } 

This game will eventually be in multiplayer. If you can fix this then you are truly awesome.