using UnityEngine;
using System.Collections;

public class SpawnPrefab : MonoBehaviour {

  public GameObject prefabs;

    public Transform borderUp;
    public Transform borderD;
    public Transform borderL;
    public Transform borderR;

    void Start () {
  InvokeRepeating("Spawn", 2, 3);
    }

    void Spawn() {
  int x = (int)Random.Range(borderL.position.x,
                            borderR.position.x);

  int y = (int)Random.Range(borderD.position.y,
                            borderUp.position.y);

  Instantiate(prefabs, new Vector2(x, y), Quaternion.identity);
           
           
    }
}

public GameObject ObjectToSpawn;   
    void SpawnObject () {                     
            Vector3 rndPosWithin;
            rndPosWithin = new Vector3(Random.Range(-1f, 1f), Random.Range(-1f, 1f), Random.Range(-1f, 1f));
            rndPosWithin = transform.TransformPoint(rndPosWithin * .5f);
            Instantiate(ObjectToSpawn, rndPosWithin, transform.rotation);      
        }
    }
}