Destroying specific game object. HELP!!!

How can i destroy a specific game object

Script:
var PickupGUI : Transform;

function Start () {

}

function Update () {

}

function OnMouseEnter ()
	{
		
    Instantiate (PickupGUI);
	
	}
	
function OnMouseExit ()
	{
	
	Destroy(PickupGUI);
	
	}

You are trying to destroy the prefab object you use for instantiation, not the object you actually instantiated. Store the object returned by Instantiate(), and then destroy that instead.