# If object is bellow another object… do something [closed]

I have 2 objects in scene. When pillar is bellow target, pillar object needs to animate. I get this error: "NullReferenceException: Object reference not set to an instance of an object".

var pillar : GameObject;
var target : GameObject;

public var triggered : boolean = false;

function OnTriggerEnter() { triggered= true; }
function OnTriggerExit()  { triggered= false;}

function Update(){
if (triggered && Input.GetKeyDown(KeyCode.JoystickButton1)){
if(target.transform.position.y > pillar.transform.position.y){
pillar = GameObject.Find("Pillars");
pillar.animation.Play();
}
}
}

• Learn to use the debugger. Also reading the error message helps. It tells you exactly what's wrong and contains a line number to tell you exactly where it's going wrong. In this case it'll tell you you're trying to access a member variable of a null object. Just a quick look at your code makes it clear that you're trying to use pillar.transform.position.y before telling the program what pillar is. Programs execute top to bottom. – MichaelHouse Aug 6 '14 at 18:06

In your second if you access the pillar and you set it to an object.

When you try to access the pillar-Object, it never has been set and as such is initialized with null. This is your error.

//first if
{
tempPillar = GameObject.FindGameobjectWithTag ("Pillars");
//second if with tempPillar!
{
pillar =tempPillar;
//play Animation
}
}