i was trying to make a alternative script to "this"

here's the script, the GUI's works but it isn't saving, would be happy if somebody could help:)

var playerX : float = 2119.7;
var playerY : float = 20.12;
var playerZ : float = 2770.62;
var playerPosition : Transform;
var player : GameObject;
var inRange = 0;
var onSave : boolean = false;

function Awake () {
    PlayerPrefs.SetFloat("playerX",playerX);
    PlayerPrefs.SetFloat("playerY",playerY);
    PlayerPrefs.SetFloat("playerZ",playerZ);
}

function Start () {
    playerPosition.transform.position.x = (PlayerPrefs.GetFloat("playerX"));
    playerPosition.transform.position.y = (PlayerPrefs.GetFloat("playerY"));
    playerPosition.transform.position.z = (PlayerPrefs.GetFloat("playerZ"));
}

function Update () {        
    playerX =(playerPosition.transform.position.x);
    playerY =(playerPosition.transform.position.y);
    playerZ =(playerPosition.transform.position.z);

    if(onSave == true){    
        PlayerPrefs.SetFloat("playerX",playerX);
        PlayerPrefs.SetFloat("playerY",playerY);
        PlayerPrefs.SetFloat("playerZ",playerZ);
    }
}

function OnTriggerEnter () {    
    inRange = 1;    
}

function OnTriggerExit () {    
    inRange = 0;    
}

function OnGUI () {    
    if(inRange == 1){
        if(GUI.Button(Rect(300,40,400,50), "SAVE!!!")){
            onSave = true;
        }
    }    
}

function loadstuff () {
    playerPosition.transform.position.x = (PlayerPrefs.GetFloat("playerX"));
    playerPosition.transform.position.y = (PlayerPrefs.GetFloat("playerY"));
    playerPosition.transform.position.z = (PlayerPrefs.GetFloat("playerZ"));    
}