rigidbody.AddForceAtPosition

I have this script:

var ForceX : float = 0;
var ForceY : float = 2;
var ForceZ : float = 0;

var positionx : float = 0;
var positiony : float = 0;
var positionz : float = 0;

function FixedUpdate () {

	if(Input.GetKey(KeyCode.Tab)){
		rigidbody.AddForceAtPosition(Vector3(ForceX,ForceY,ForceZ), Vector3(transform.position.x - positiony, transform.position.y - positionx, transform.position.z - positionz)); 
	}
}

This is supposed to fin the position on the object, then addforce at that point. But the weird thing is, no matter what i set the values too, it doesn’t work. Any ideas?

There is nothing wrong with your code in principle. A force of 2 Newtons might be too small to have an effect. How heavy is the rigidbody? What is the friction with the surface is it resting upon? These are factors that will counter such a force.