OnTriggerEnter - Melee Combat

Can someone explain how this is done please? I'm trying to do melee combat for my game and I have animated my sword to swing. I've never used this before and have no idea how to implement it and the api isn't very helpful.

I have added an empty object and a box collider around the blade of the sword. I've added it as a child of the sword and have ticked Is Trigger. This is the script I have so far.

 function OnTriggerEnter ( other : Collider )
 
 {
 
     if ( other.tag == "Enemy" ) // or what ever you want to identify the object
 
     {
 
         other.GetComponent("EnemyHealth1").AdjustCurrentHealth(-10);
 
         Debug.Log("Enemy Hit!!");
 
     }
 
 }

But it doesn't seem to be doing anything.

This is the script for the health and AdjustCurrentHealth

 var hp:float; // health value, 0..maxHp
 
 var maxHp:float; 
 
 var healthBarWidth:int = 20;
 
 var myHealthBar:GameObject;
 
 private var myHb:GameObject;
 
 var posX:float;
 
 var posY:float;
 
 var show: float = 0;       // health bar appears when show > 0
 
 var duration: float = 0.6; // health bar vanishes for duration seconds
 
 
 
 function Start () {
 
   myHb = Instantiate(myHealthBar, transform.position, transform.rotation);
 
 
 
 }
 
 
 
 function AdjustCurrentHealth(adj : int) {
 
    hp += adj;
 
 }
 
 
 
 function Update () {
 
   if (show>0){
 
     myHb.guiTexture.color.a = show; // variable show controls the bar alpha
 
     show -= Time.deltaTime/duration; // fades out health bar unless show is recharged
 
     myHb.transform.position = Camera.main.WorldToViewportPoint(transform.position);
 
     myHb.transform.position.x -= posX;
 
     myHb.transform.position.y -= posY;
 
   //  myHb.transform.localScale = Vector3.zero; // <- this does nothing
 
     var healthPercent:float = Mathf.Clamp(hp / maxHp, 0, 1);
 
     myHb.guiTexture.pixelInset = Rect (0.02, -0.09, healthBarWidth * healthPercent, 5);
 
   }
 
 }

The health script is attached to my enemy and the melee attached the the empty game object with the box collider.