How to instantiate multiple clones of the same prefab ?

How do I change the codes below in such a way that the artist can control the number clones of the same prefab by changing a variable in the scene ? Can anyone kindly help me ? Thanks .

using UnityEngine;
using System.Collections;

public class TileInstantiation : MonoBehaviour {
	
	// Use this for initialization
	void Start ()
	{
		GameObject Obj = (GameObject)Instantiate( Resources.Load("Ground") );
	}
	
	// Update is called once per frame
	void Update ()
	{
	}
}

var numberOfObjects : int = 10;
var waitTime : float = 1.0;

var evilSphere : GameObject;
 
function Start () {
    //You will have problems if you put this in Update b/c it will happen every frame.
    // Any other function is fine.
    Spawn ()
}
 
function Spawn () {
     for (var i = 0; i < numberOfObjects; i++) {
          var spawnPos : Vector3 = new Vector3(i, 0, 0);
          Instantiate(evilSphere, spawnPos, Quaternion.Identity);
          //Spawn a new Object.  I spaced them out so it is easier to see.
 
          yield WaitForSeconds(waitTime);
          //Wait 'x' seconds before repeating the loop.
          // You will get a slightly different behavior if you yield @ the beginning
     }
}