Instantiate problem in a RTS game

I'm working on an RTS game right now and I encountered a problem when making my game, this is my code. #pragma strict

 var CircuitBoard : GameObject;
 var CircuitBoardGhost : GameObject;
 
 function Start () {
 
 }
 
 function OnMouseUp () {
 
     if (CircuitBoardGhost.gameObject.activeInHierarchy == true)    {
     
         Instantiate (CircuitBoard, transform.position, transform.rotation);
         CircuitBoardGhost.gameObject.SetActive(false);
     
     }
 
 }

What I want to do is when I click on the CircuitBoardGhost which is a ghost block is to make it disappear and to make the actual CircuitBoard appear, when I try this it just won't remove the CircuitBoardGhost and won't instantiate the CircuitBoard. Any help would be really appreciated, thanks. ;)