Joystick input only moves object diagonally

Question

I have a problem with the singe joystick script usage in Unity.

I use the below script for the movement of a chopper via a rigidbody. When I test the game in unity with the arrow keys, everything works perfectly as expected. However, if I test this on a phone, the chopper only moves diagonally from bottom left to top right.

I am sure it has to do with the way I attach the joystick to the X nd Y axis, but I fail to spot my mistake....can anyone look at this with a fresh pair of eyes and tell me where I screw up?

    #pragma strict

var speed : float = 500.0;
var smooth : float = 2.0;
var gravity : float = 0.0;
var moveJoystick : Joystick;


    function FixedUpdate () {

    var horPos = Input.GetAxis ("Horizontal") ? 
                   Input.GetAxis ("Horizontal") : joyStickInput(moveJoystick);
var verPos = Input.GetAxis ("Vertical") ? 
                 Input.GetAxis ("Vertical") : joyStickInput(moveJoystick);


    var movedirection = new Vector3(horPos, 0, verPos);

if (movedirection != Vector3.zero){
        var newRotation = Quaternion.LookRotation(movedirection * -1);
        transform.rotation = Quaternion.Slerp(transform.rotation, newRotation,     Time.deltaTime * smooth);
        }
    rigidbody.AddForce (movedirection * speed * Time.deltaTime);
     }

    function joyStickInput (joystick : Joystick) {
   var absJoyPos = Vector2 (Mathf.Abs(joystick.position.x),
                               Mathf.Abs(joystick.position.y));
   var xDirection = (joystick.position.x > 0) ? 1 : -1;
   var yDirection = (joystick.position.y > 0) ? 1 : -1;
   return ( ( absJoyPos.x > absJoyPos.y) ? absJoyPos.x * xDirection : absJoyPos.y * yDirection);
   }

Answer 1

Because horPos and verPos use the same joyStickInput(moveJoystick) ?

When press right button, your joyStickInput() will return 1 set horPos and verPos to the same value(1), and it will make your sprite moving toward top(y+1) right(x+1)