void OnCollisionEnter2D(Collision2D col)
        {
        if (col.gameObject.tag == "HardFloor" && col.relativeVelocity.magnitude > 100)
            {
                Debug.Log ("There has been a collision!");
                Destroy (col.gameObject);
            }
            if (col.gameObject.tag == "otherTarget")
            {
                Debug.Log ("There has been a collision!");
                Destroy (col.gameObject);
            }
        }