public void SpawnFireBall()
{
if (fireBall != null)
{
GameObject ball = Instantiate(fireBall, transform.position, Quaternion.identity);
FireBall fir = ball.GetComponent <FireBall>();
Transform t = FindClosestTarget();
fir.SetDamage(damage);
if (t != null)
{
// note t may be destroyed
fir.SetDirection(-(transform.position - t.position));
}
}
}