private var targetPosition:Vector3;

function Update () {

		// get the speed variable
		var engine : myEngine;
		engine = gameObject.GetComponent("myEngine.speed");

    if(Input.GetKey(KeyCode.Mouse1))
	//so that only when the key is pressed is the ship moving
    {

        var playerPlane = new Plane(Vector3.up, transform.position);
        var ray = Camera.main.ScreenPointToRay (Input.mousePosition);
        var hitdist = 0.0;

        if (playerPlane.Raycast (ray, hitdist)) {
            var targetPoint = ray.GetPoint(hitdist);
            targetPosition = ray.GetPoint(hitdist);
            var targetRotation = Quaternion.LookRotation(targetPoint - transform.position);
            transform.rotation = targetRotation;
        }
    }

    transform.position = Vector3.MoveTowards (transform.position, targetPosition, Time.deltaTime * engine.speed);
}