Spawning Cube on empty gameobject

Ok I’ve had this problem for a while now, basically I am trying to spawn a cube prefab on a empty game object.Here is my script.

using UnityEngine;
using System.Collections;

public class Spawner : MonoBehaviour{

	 public GameObject Cube; 
	public float spawnTimeDelay = 3f;
	public float spawnTimeInGame = 2f;
	public Vector3 spawnLocation = new Vector3 (0,2,0);

	void Spawn () 
	{
		GameObject SpawnLocation = (GameObject) Instantiate ( Cube, spawnLocation, Quaternion.identity);
	}



	

		
		
	// Use this for initialization
	void Start  ()
	{
		InvokeRepeating ("Spawn", spawnTimeDelay, spawnTimeInGame);
	}
}

Try it with:

cube=GameObject.CreatePrimitive(PrimitiveType.Cube);
cube.transform.position = new Vector3(transform.position.x,transform.position.y,transform.position.z);