Space Shooter Asteroids Not Being Destroyed

I downloaded unity 5 and completed Roll a Ball tutorial,Then I started the Space Shooter project,Everything went fine until step 9-Creating Hazards.
I made the asteroid and written the scripts according to the video tutorial and it was tumbling fine but isn’t being destroyed. when I shoot the laser,the laser get pasts it and nothing happens to the laser and asteroid.
Help Me!

These are the scripts:

DESTROY BY CONTACT:

using UnityEngine;
using System.Collections;

public class DestroyByContact : MonoBehaviour
{
	void onTriggerEnter(Collider other) {
		if (other.tag == "Boundary") 
		{
			return;
		}
		Destroy(other.gameObject);
		Destroy(gameObject);
	}
}

MOVER:

using UnityEngine;
using System.Collections;

public class Mover : MonoBehaviour 
{
	public float speed;

	void Start ()
	{
		GetComponent<Rigidbody>().velocity = transform.forward * speed;
	}
}

PLAYER CONTROLLER:

using UnityEngine;
using System.Collections;

[System.Serializable]
public class Boundary
{
	public float xMin, xMax, zMin, zMax;
}

public class PlayerController : MonoBehaviour 
{
	public float speed;
	public float tilt;
	public Boundary boundary;

	public GameObject shot;
	public Transform shotSpawn;
	public float fireRate;

	private float nextFire;

	void Update ()
	{
		
		if (Input.GetButton("Fire1") && Time.time > nextFire)
		{
			nextFire = Time.time + fireRate;
//			GameObject clone = 
			Instantiate(shot, shotSpawn.position, shotSpawn.rotation); //as GameObject;
		}
	}
	void FixedUpdate ()
	{
		float moveHorizontal = Input.GetAxis ("Horizontal");
		float moveVertical = Input.GetAxis ("Vertical");
		
		Vector3 movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);
		GetComponent<Rigidbody>().velocity = movement * speed;
		
		GetComponent<Rigidbody>().position = new Vector3 
			(
				Mathf.Clamp (GetComponent<Rigidbody>().position.x, boundary.xMin, boundary.xMax),
				0.0f,
				Mathf.Clamp (GetComponent<Rigidbody>().position.z, boundary.zMin, boundary.zMax)
				);
		
		GetComponent<Rigidbody>().rotation = Quaternion.Euler (0.0f, 0.0f, GetComponent<Rigidbody>().velocity.x * -tilt);
	}
}

RANDOM ROTATOR:

using UnityEngine;
using System.Collections;

public class RandomRotator : MonoBehaviour
{
	public float tumble;

	void Start ()
	{
		GetComponent<Rigidbody>().angularVelocity = Random.insideUnitSphere * tumble;
	}
}

DESTROY BY BOUNDARY:

using UnityEngine;
using System.Collections;

public class DestroyByBoundary : MonoBehaviour
{
	void OnTriggerExit(Collider other) {
		Destroy(other.gameObject);
	}
}

I am not getting any errors and I’m using Unity 5.

I didn’t see the video but I think you just forgot to add a Collider to the asteroid or to the laser. (on the inspector)

If you added it then you didn’t tick the “Is Trigger” box.

I believe your problem will be fixed if you change the capitalization to “OnTriggerEnter” (That’s what worked for me!)

@AbdulSammad Make sure that the name of the scripts in your (Assets/Scripts) folder matches the name of your classes in your code. it is case sensitive.

Let us know if this worked.