Change level on trigger

I've added this code to try to change the level when the character enters the trigger but it isn't working for some reason. I've got a box collider set to is trigger and added a rigidbody.

using UnityEngine;
using System.Collections;
public class Leveltrigger : MonoBehaviour {
void OnTriggerEnter(Collider other) { Application.LoadLevel(2); } }

Any help would be great Thanks