javascript to respawn player in 2d platformer not working

Hey, this is my first time n unity answers so please tell me if i'm doing something wrong. I'm creating a 2d platform game and I have a JavaScript respawn script. It checks if the player is at y -80, and if that's true it restarts the scene. Anyway, I get this error: `Assets/respawn.js(8,24): BCE0020: An instance of type 'UnityEngine.GameObject' is required to access non static member 'transform'.

this is my script: (I added it to my player)

 #pragma strict
 
 function Start () {
 
 }
 
 function Update () {  
     if (GameObject.transform.position.y <= -80)  
     {  
         Application.LoadLevel("main");  
     }  
 }

(sorry the code option markup didn't work so I did it like this)