void OnTriggerEnter2D (Collider2D col){
//Debug.Log ("Hit!!!");
if (col.IsTouching(gameObject.GetComponent<Collider2D>())) {
Rigidbody2D targetRigidbody = col.GetComponent<Rigidbody2D> ();
Enemy targetHealth = targetRigidbody.GetComponent<Enemy> ();
if (targetHealth != null) {
targetHealth.TakeDamage (dmg);
ParticleSystem particles = Instantiate (explosionParticles, transform.position, transform.rotation) as ParticleSystem;
particles.Play ();
hitSound.Play();
Destroy (gameObject, 0.5f);
}
}
}