Bullets not spawning (Instantiate)

Been following this tutorial: https://www.youtube.com/watch?v=VkNUDn7rdPY∈dex=13&list=PL5MghP-s6HUahXF3ss5wjseBCal9UpH_9

Unfortunately, no bullets spawn when hit the left mouse button.

Current script:

 var mountObject : GameObject;
 var player : GameObject;
 var cameraMain : GameObject;
 @HideInInspector
 var gunXRotation : float;
 @HideInInspector
 var gunYRotation : float;
 var zoomAngle : float = 24;
 
 var fireSpeed : float = 15;
 @HideInInspector
 var waitTillNextFire : float = 0;
 var bullet : GameObject;
 var bulletSpawn : GameObject;
 
 function Upddate ()
 {
     if(Input.GetButton("Fire1"))
     {
         if(waitTillNextFire <= 0)
         {
             if(bullet)
                 Instantiate(bullet, bulletSpawn.transform.position, bulletSpawn.transform.rotation);
             waitTillNextFire = 1;
         }
     }
     waitTillNextFire += Time.deltaTime * fireSpeed;
 }
 
 function LateUpdate () 
 {
     cameraMain.GetComponent(MouseLook).currentTargetCameraAngle = zoomAngle;
         
     gunXRotation = cameraMain.GetComponent(MouseLook).currentXRotation;
     gunYRotation = cameraMain.GetComponent(MouseLook).currentYRotation;
 
     transform.position = mountObject.transform.position;
     transform.rotation = mountObject.transform.rotation;
     
     if (player.GetComponent(PlayerMovement).weaponReady == true)
     {
         mountObject.transform.rotation = Quaternion.Euler(gunXRotation, gunYRotation, 0);
     }
 }