Error BCE0019

Hi, so im new at this and im making a survival game, this code is for the playerGUI and/or my FPS Arms Here is the code.

Code:

 #pragma strict
 
 private var hasAxe : boolean = false;
 
 private var canSwing : boolean = true;
 private var isSwinging : boolean = false;
 var swingTimer : float = 0.7;
 
 private var controller : CharacterController;
 private var playerGUI : PlayerGUI;
 
 function Start()
 {
     hasAxe = true;
     controller = GameObject.Find("First Person Controller").GetComponent(CharacterController);
     playerGUI = GameObject.Find("First Person Controller").GetComponent(PlayerGUI);
 }
 
 function Update()
 {
     //If we aren't moving and if we aren't swinging, then we idle!
     
     if(controller.velocity.magnitude <= 0 && isSwinging == false)
     {
         GetComponent.<Animation>().Play("Idle");
         GetComponent.<Animation>()["Idle"].wrapMode = WrapMode.Loop;
         GetComponent.<Animation>()["Idle"].speed = 0.2;
     }
     
     //If we're holding shift and moving, then sprint!
     
     if(controller.velocity.magnitude > 0 && Input.GetKey(KeyCode.LeftShift))
     {
         GetComponent.<Animation>().Play("Sprint");
         GetComponent.<Animation>()["Sprint"].wrapMode = WrapMode.Loop;
     }
     
     //WOODCUTTING SECTION
     if(hasAxe == true && canSwing == true)
     {
         if(Input.GetMouseButtonDown(0))
         {
             //Stamina reduction applied to the PlayerGUI script
             playerGUI.staminaBarDisplay -= 0.1;
             
             //Swinging animation
             GetComponent.<Animation>().Play("Swing");
             GetComponent.<Animation>()["Swing"].speed = 2;
             isSwinging = true;
             canSwing = false;
         }
     }
     
     if(canSwing == false)
     {
         swingTimer -= Time.deltaTime;
     }
     
     if(swingTimer <= 0)
     {
         swingTimer = 1;
         canSwing = true;
         isSwinging = false;
     }
 }

Error: Assets/Animations/Part 3 - Animations_Arms/PlayerGUI.js(44,35): BCE0019: 'staminaBarDisplay' is not a member of 'PlayerGUI.

Why does it keep on saying' "staminaBarDisplay' is not a member of 'PlayerGUI."?