public class MoveLeftConstantly : MonoBehaviour {

	float posX;
	float posY;
	float speed = 0.1f;

	// Use this for initialization
	void Start () {
		posY = transform.position.y;
		posX = transform.position.x;

	}

	// Update is called once per frame
	void Update () {

		transform.position = new Vector3 (posX, posY, 0);
		posX -= speed;
		if (posX < -7f) {
			posX = 7f;
		}
	}