void Update () {

        //this should make the line, why not working?
Vector3 forward = transform.forward;
Debug.DrawRay(transform.position, forward);
Debug.DrawLine(transform.position, transform.position + forward * 10000);


        if (Input.GetMouseButtonDown (0)) {

            //
            Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
            RaycastHit hit;

            if (Physics.Raycast(ray, out hit, 100.0f)){

                //


                //
                Vector3 startPos = transform.position;
                Vector3 clickPos = new Vector3(hit.point.x, hit.point.y, transform.position.z);
                Vector3 direction = Direction (clickPos - startPos);

                //direction
                rb.velocity = new Vector3(direction.x * 5, direction.y * 5, 0);


            }



        }



    }