an object seemingly cannot access a value in other.

A drill in the game is supposed to only fire if the players fuel value is equal or greater than the cost to run it. It's strange because i've done this before, but it doesn't work for this one. anyone know what's wrong? the error is at the line,

         if(fuels.fuel >= fuelcost){



 var holder : GameObject;
 var fuels : Playerstuff;
 
 var reapirthing : GameObject;
 
 var fuelcost : int = 1;
 
 
 function Update () {
 
 
 if(Input.GetButtonUp("Fire1")){
         if(fuels.fuel >= fuelcost){
             
             fuels.fuel = fuels.fuel - fuelcost;
         
             var instance : GameObject = Instantiate(reapirthing, transform.position, transform.rotation); 
             
             
             }
         }
 }
 
 
 function Start(){
 
 holder = GameObject.FindGameObjectWithTag("Player");
 fuels = holder.Playerstuff;
 
 }