Spaceshooter enemy spawning problem

Hi Unity answers.
I am trying to make a space shooter but i cant get the enmy to spawn. i have checked my script through so many times but i can not find the problem. here is my script.

using UnityEngine;
using System.Collections;

public class GameController : MonoBehaviour

{

public GameObject hazard;
public Vector3 spawnValues;

void start ()
{
	SpawnWaves ();
}

void SpawnWaves ()
{
	Vector3 spawnPosition = new Vector3(Random.Range(-spawnValues.x,spawnValues.x), spawnValues.y, spawnValues.z);
	Quaternion spawnRotation = Quaternion.identity;
	Instantiate (hazard, spawnPosition, spawnRotation);
}

}

The Start() function is case sensitive: it looks like in your code it uses a lower case ā€˜sā€™ so it will never be executed.