void Update () {
    float disX = Input.GetAxis ("Horizontal") * sensitivity * Time.deltaTime;
    float disZ = Input.GetAxis ("Vertical") * sensitivity * Time.deltaTime;
    Vector3 move = new Vector3 (disX, 0, disZ);
    move = transform.TransformDirection (move);
    _charController.Move (move);
}

void Update () {
    _rotationX -= Input.GetAxis ("Mouse Y") * sensitivity * Time.deltaTime;
    _rotationY += Input.GetAxis ("Mouse X") * sensitivity * Time.deltaTime;
    transform.localEulerAngles = new Vector3(_rotationX, _rotationY, 0);
}