iphone/ipad Gyro perpendiculat and moving FPC

I am working on a project and i want my FPC to walk in a scene based on gyro input. My problem is that i don't know how to make it work perpendicular to the ground and not parallel.

I am using Input.gyro to look around me and for walking i am using the standard walking script with gyro.gravity as import and a GUI texture to enable/disable walking.

Looking around script is :

 function Update () {
 if (gyroBool  && !fpc.walk) {
     var camRot : Quaternion = gyro.attitude * rotFix;
     transform.localRotation = camRot;
 }
 }

Where gyroBool tests if the gyro is available and fpc.walk is checking if the walking arrow wasn't touch.

FPC walk :

 function FixedUpdate() {
 if (grounded) {
     moveDirection = new Vector3 (gyro.gravity.y, 0,gyro.gravity.x);
     moveDirection = transform.TransformDirection(moveDirection);
     moveDirection *= speed;
 }    // Apply gravity
 moveDirection.y -= gravity * Time.deltaTime;
 if (walk){// Move the controller
     var controller : CharacterController = GetComponent(CharacterController);
     var flags = controller.Move(moveDirection * Time.deltaTime);
     grounded = (flags & CollisionFlags.CollidedBelow) != 0;
 }
 }
 function Update() {
 if (Input.touchCount > 0){
     var touch = Input.GetTouch(0);
     if (touch.phase == TouchPhase.Began && arrow.HitTest(touch.position)){
         walk = true;
     }
     if (touch.phase == TouchPhase.Ended || touch.phase == TouchPhase.Canceled){
         walk = false;
     }
 }
 }

Any idea on how to make it walk standing ?