How to debug this shopkeeper script ?

Hello, I am making a RPG game but as I am new to unity then I stumbled on a problem that I cannot figure out myself. I made a shopkeeper script that would work for many shopkeepers. The problem is that when I click different shopkeepers they all give the same layout of items although I have but different numbers for the script on different shopkeepers. At the beginning I thought that it isn't working at all but then I realized that although the layout is always the same the items are as I put them for every shopkeeper. So it kinda works only the layout of items has the problem.

 var hit : RaycastHit;
 static var shopOpen : boolean = false;
 var texture : Texture2D;
 var shopSize = Rect(50, 50, 400, 500);
 var items : int[]; //This is where I put the item numbers for every shopkeeper
 static var shopList : List.<ItemClass> = new List.<ItemClass>(); // this is where all the items for shops are listed
 var myTransform : Transform; //current transform data of this enemy
 var target : Transform;
 var shopDistance : int = 5;
 private var slotNR : int = 0;
 
 function Awake (){
     myTransform = transform; //cache transform data for easy access/preformance
 }
 
 function Start (){
     target = GameObject.FindWithTag("Player").transform; //target the player
 }
 
 function OnGUI () {
     if(shopOpen == true){
         shopSize = GUI.Window(3, shopSize, ShopWin, texture);
     }
 }
  
 function Update () {
     var distance = (target.position - myTransform.position).magnitude;
     if(distance < shopDistance){
         if(Input.GetMouseButtonDown(0) &&
                collider.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), hit, Mathf.Infinity)) {
             //enable shop    
             shopOpen = true;
         }
     }
 //    if(distance > shopDistance){
 //        shopOpen = false;
 //    }
 }
 
 function ShopWin(){
     if(GUI.Button(Rect(375, 0, 25, 25), "X")){
         shopOpen = false;
     }
     // For recognizing the slot
     slotNR = 0;
     //y is row nr
     for(var y = 0; y < 2; y++){
         GUILayout.BeginHorizontal();
         //x is columnt nr
         for(var x = 0; x < 6; x++){
             xPosition = 12 + (x * 62);
             yPosition = 30 + (y * 62);
             //Shop slots. If clicked they check what item it is in the slot and then corresponds to it
             if(GUI.Button(Rect(xPosition, yPosition, 60, 60), shopList[items[slotNR]].icon)){
                 Inventory.Coins -= 50;
                 Inventory.playerInventory.Add(shopList[items[slotNR]]);
                 return;
             }
             slotNR++;
         }
         GUILayout.EndHorizontal();
     }
 
     GUI.DragWindow();
 }

I would be very thankful for any kind of hints :)