Melee Attacking script doesn't work

Hey guys, beginner here. I recently attempted to make my players take damage when two objects collided. When one player would press the attack button, the gameobject that I created (to represent the sword of the player) ‘touches’ player2. However, nothing happens. I’m sure that class playerattack works, but class attacktrigger doesn’t. Thank you

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerAttack : MonoBehaviour {
	private bool attacking = false;

	private float attackTimer = 0;
	private float attackCd = 0.3f;

	public Collider2D NinjaAttackTrigger;

	private Animator anim;

	void Awake(){

		anim = gameObject.GetComponent<Animator>();
		NinjaAttackTrigger.enabled = false;
	}
	void Update() {
		if (Input.GetKeyDown (",") && !attacking) {
			attacking = true;
			attackTimer = attackCd;

			NinjaAttackTrigger.enabled = true;

		}
		if (attacking) {

			if (attackTimer > 0) {
				attackTimer -= Time.deltaTime;

			}
			else {
				attacking = false;
				NinjaAttackTrigger.enabled = false;
			}
		}
		anim.SetBool("Attacking", attacking);
	}

}

ATTACK TRIGGER STARTS HERE

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class AttackTrigger : MonoBehaviour {

	public int dmg = 10;

	void onTriggerEnter2D (Collider2D col) {

		if(col.isTrigger == true && col.CompareTag("Knight")) {
			col.SendMessageUpwards ("Damage", dmg);
			dmg--;
			print("working");
	}
	}

			}

Change onTriggerEnter2D to OnTriggerEnter2D (Capital O) :slight_smile: