My Trigger Event is not working

Ok so I want to make a door that will open if get near it and I have 2 door sprites setup (one for an open door and one for a closed one). The door itself has 2 colliders one that you can collide with and one that is a circle collider witch I use as a trigger. If you activate the collider then the sprite should change and the main collider should deactivate. But the OnTriggerEnter event in my script isn´t working I have tried debugging it for quite some time. I really need help. Thanks

Heres the code for the Door.

´using UnityEngine;
using System.Collections;

public class Door_Logic : MonoBehaviour
{
    public Collider2D collisionCollider;
    public Sprite closed;
    public Sprite open;
    SpriteRenderer sprRender = new SpriteRenderer();

    void OnTriggerEnter (Collider col)
    {
        if(col.gameObject.tag == "Player")
        {
            sprRender.sprite = open;
            collisionCollider.enabled = false;
        }
        else
        {
            sprRender.sprite = closed;
            collisionCollider.enabled = true;
        }
    }
}

Never mind I have figured it out I had to set OnTriggerEnter to OnTriggerEnter2D and the collider to a 2D collider.