Player take damage on collision with AI

I am new to coding and I am trying to make my player take damage when an AI touches it, this is my code so far:

   var maxHealth = 100;
       public static var currentHealth = 100;
       var PlayerHealthDisplay : GUIText; 
       function Start() {
           DisplayAmount();
       }
       
       function DisplayAmount () {
           PlayerHealthDisplay.text = ""+ currentHealth;
       }
      function OOnTriggerEnter(collider:Collider) {
          if (collider.tag == "beep"){
               
               currentHealth += -10;
               PlayerHealthDisplay.text = ""+ currentHealth;
           }
       }
            
           

 

The player does not take any damage though, how should I change it?