i want to generate random coin at runtime

i did some work but coin is generating at only place and limited can anyone tell m whats the mistake in this using UnityEngine; using System.Collections;

public class Random_coin : MonoBehaviour { public GameObject ObjectToSpawn; public int RandomRangeMax=30; public int ItemsToSpawn=20; public float ObjectLifeTime=120; public Vector3 Offset=Vector3.zero; //public Vector3 OffsetRandom=Vector3.zero; public float SpawnEverySecs=2.0f; public float WaitBeforeStartSpawning = 2.0f; public bool RandomOn=false; public int MaxInScene = 100; public string STRTag = "Enemy_ground";

 GameObject GOShot;
 int SpawnedItems=0;
 float TimeFromLastSpawn=2000.0f;
 bool Started = false;
 bool Spawn = false;


 // GameObject[] GOs;

 // Use this for initialization
 void Start () 
 {
     InvokeRepeating("RandomSpawn", WaitBeforeStartSpawning, SpawnEverySecs);
 }
 
 // Update is called once per frame
 void RandomSpawn()
 {

     if (SpawnedItems < ItemsToSpawn)
     {
         Spawn = false;
         if (!RandomOn)
             Spawn = true;
         else
             if (Random.Range(0, RandomRangeMax) == 1) Spawn = true;
         if (Spawn)
         {
             GameObject[] GOs = GameObject.FindGameObjectsWithTag(STRTag);
             //Debug.Log(this.gameObject.tag+" "+GOs.Length);
             if (GOs.Length < MaxInScene)
             {
                 SpawnedItems++;
                 if (ObjectToSpawn)
                     GOShot = Instantiate(ObjectToSpawn, this.transform.position + Offset, Quaternion.identity) as GameObject;
                 if (ObjectLifeTime > 0.0f)
                 if (GOShot)
                     Destroy(GOShot, ObjectLifeTime);
             }
             //else                   Debug.Log("Spawn skipped");
         }
     }
 }

}