teleportation problems (2d)

i want to make an enemy that when touched teleports the player to x0 y4 zn/a here is what I have:
using UnityEngine;
using System.Collections;

public class kill_player : MonoBehaviour
{
    public GameObject player;
    void OnCollisionEnter(Collision col)
    {
        if (col.gameObject.name == "murder")
        {
            player.transform.position = new Vector2(0, 4);
        }
    }
}

what makes it not work? and is it not the script?

Make sure you have the player variable set in the inspector. Then try this.

public class kill_player : MonoBehaviour
     {
         public GameObject player;
         void OnCollisionEnter(Collision col)
         {
             if (col.gameObject == player)
             {
                 player.transform.position = new Vector2(0, 4);
             }
         }
     }