control amount of instantiated objects in getmousebutton

[IMTRIGGERHAPPY9]

does anybody have any ideas on how to control an instantiated objects count? i am lost and could use some help please.

if(Input.GetMouseButton(0)){

    				var thisTower = Instantiate(tower1,gridPoint,Quaternion.identity);
    				thisTower.transform.position = gridPoint.position;
    				}

[syclamoth]

EDIT- I'm afraid I didn't really understand your question to begin with, but now I've got a much better answer for you!

private var ghostTower : Transform;

function Update()
{
    if(Input.GetMouseButtonDown(0))
    {
        ghostTower = Instantiate(transparentTower,gridPoint.position,Quaternion.identity).transform;
        ghostTower.transform.position = gridPoint.position;
    }
    if(Input.GetMouseButton(0))
    {
        if(ghostTower != null)
            ghostTower.position = gridPoint.position;
        }
    }
    if(Input.GetMouseButtonUp(0))
    {
        Destroy(ghostTower);
        Instantiate(realTower, gridPoint.position, Quaternion.identity);
    }
}

This has the added advantage of preventing the 'ghost towers' from attacking while they are being placed- since the ghost towers aren't actual towers, they don't target things when you are dragging them around. This prevents at least one gameplay exploit!

EDIT I’m not all that clear on exactly how Instantiate works in Javascript- because of the weak typing, I’m not sure exactly what gets returned. I assume it just guesses based on they type you are assigning to, but I’m not completely certain.