i can't kill the emeny ai

I’m working on a simple combat script. I set up the enemy ai to patrol a waypoint and do damage to the player and also take damage. I can’t get the ai to lose any damage when it is hit with the prefab I made. If anyone can point a mistake I made in this script it would be much appreciated.

public var path1 : Transform;
public var path2 : Transform; 
public var speed : float = 2;
public var maxHealth  : float = 1;


private var target : Transform;
private var controller : CharacterController;
private var currentHealth : int = maxHealth;


function Start()
{
	SetTarget(path1);
	controller = GetComponent(CharacterController);
	currentHealth = maxHealth;
}

function Update()
{
	//look at the target
	var Look : Vector3 = new Vector3(target.position.x, this.transform.position.y, target.position.z);
	transform.LookAt(Look);
	// move
	controller.SimpleMove(transform.forward*speed);
	}
}
function SetTarget(newTarget : Transform) : void
{
	target = newTarget;
}

function OnTriggerEnter(node : Collider) : void
{
	if (node.transform == target)
		{
		if (target == path1)
			SetTarget(path2);
		else if (target == path2)
			SetTarget(path1);
		} 
}
function OnTirggerEnter(other : Collider) 
{
if(other.tag == "shot")
{
 currentHealth -5;
  }
  }

function ModiflyHeath(change : float)
{
	currentHealth += change;
	if (currentHealth > maxHealth)
	{
		currentHealth = maxHealth;
	}
	if (currentHealth <= 0)
	{
		Destroy(this.gameObject);
	}
}

The first and most serious problem is that you have a function called ‘OnTirggerEnter()’. The function is called ‘Trigger’ not Tirgger’, so it will never be called. But if you spelled it correctly, then you would have an issue because you already have an ‘OnTriggerEnter()’ function. You need to move your shot code inside the existing ‘OnTriggerEnter()’ function.

hope this helps