Inventory code not working [JS]

Hey guys I have been following this tutorial on how to make a simple inventory https://www.youtube.com/watch?v=QlF6t5gI5es . Everything works fine on my end except the texture doesn't change when I pick up an item. Like it does on the video my code

 var gridpos : Vector2 = new Vector2(10,2);
 var gridsize : Vector2 = new Vector2(323,410);
 var wood :  int = 0;
 var inventoryskin : Texture;
 var showgui : boolean = false;
 var inventoryopen : AudioClip;
 var grid : Texture[];
 var myGUI :GUISkin;
 private var gridvalue:float= -1;
 static var itemid : String[]=["wood"];
 static var itemAmount : int[] =[0];
 var itemtexture = new Texture[inventory.itemid.Length];
 function Start(){
 var textures : Object[] = Resources.LoadAll("itemicons",Texture2D);
 for(var i =0; i <textures.Length; i++)
 {
 itemtexture[i]=textures[i];
 }
 }
 
 function Update () {
 var theinventory :inventoryadditem =GetComponent(inventoryadditem);
 var textures :inventoryadditem =GetComponent(inventoryadditem);
 if(Input.GetKeyDown("i")){
 showgui = !showgui;
 if(showgui == true)
 GameObject.Find("player").GetComponent("FirstPersonController").enabled = false;
 if(showgui == false)
 GameObject.Find("player").GetComponent("FirstPersonController").enabled = true;
 }
 if(Input.GetKeyDown("i"))
 theinventory.NewItem();
 textures.NewItem();
 }
 function OnGUI () {
 if(showgui == true)
 {
 GUI.skin = myGUI;
 GUI.BeginGroup(Rect(50,200,600,500),inventoryskin);
 gridvalue = GUI.SelectionGrid(Rect(gridpos.x,gridpos.y,gridsize.x,gridsize.y),gridvalue,grid,3);
 GUI.EndGroup();
 }
 }

 

how do I fix this thx