Sup guys, how can I edit my script to flip my character depending on which way he's running/facing?

// Movement Variables
private var jumpSpeed:float = 9.0; 
private var gravity:float = 100.0; 
private var rotateSpeed:float = 250.0; 
private var grounded:boolean = false; 
private var moveDirection:Vector3 = Vector3.zero; 
private var isWalking:boolean = true; 
private var moveStatus:String = "idle"; 
private var xSpeed = 250.0; 
private var ySpeed = 120.0; 
private var yMinLimit = -40; 
private var yMaxLimit = 80; 
private var x = 0.0; 
private var y = 0.0; 

static var walkSpeed:float = 15.0; 
static var isRunning:boolean = false;
static var isMoving:boolean = false;

function Start ()
{
   // Set all animations to loop
   animation.wrapMode = WrapMode.Loop;
   animation.Stop();
}

// -------------------------------------------------------------------------------------------------------------
// ----------------------------------------------------------- UPDATE ---------------------------------------
// -------------------------------------------------------------------------------------------------------------

function Update () {
   if(grounded) { 
        moveDirection = new Vector3(0,0,Input.GetAxis("Horizontal")); 
        if(Input.GetAxis("Horizontal")) { 
            moveDirection *= .7; 
            transform.LookAt(transform.position + moveDirection); 

        } 
        moveDirection = transform.TransformDirection(moveDirection); 
        moveDirection *= walkSpeed;
        moveStatus = "idle"; 
        if(moveDirection != Vector3.zero) {
            animation.CrossFade("run",0.2);
            isMoving = true;
        } else {
            isMoving = false;
            animation.CrossFade("Take 001",0.2);
        }
    }                           
    //////////

    if(Input.GetKey("q")) {
        isRunning = true;
        walkSpeed = 50;
    }else{
        isRunning = false;
        walkSpeed = 30;
    }
    //////////

    moveDirection.y -= gravity * Time.deltaTime; 
    var controller:CharacterController = GetComponent(CharacterController); 
    var flags = controller.Move(moveDirection * Time.deltaTime); 
    grounded = (flags & CollisionFlags.Below) != 0; 
    };
    static function ClampAngle (angle : float, min : float, max : float) { 
   if (angle < -360) 
      angle += 360; 
   if (angle > 360) 
      angle -= 360; 
   return Mathf.Clamp (angle, min, max); 
} 

@script RequireComponent(CharacterController)