Index out of range exception

I cannot seem to find the array problem in my script below even though the console shows that the error is at line 35. Furthermore, I have used some similar functions from design3 inventory system tutorial with little modifications which could cause the error. I've tried converting my "items" array variable into a public variable and it doesn't work:

 var maxSlots : int;
 var invParent : Transform;
 var minSlots : int = 0;
 var newItem : Transform;
 var noItems : int;
 var full : boolean;
 var itemSelected : Transform;
 var throwTime : float;
 var style : GUISkin;
 var openInv : boolean;
 var windowRect : Rect = Rect(20, 20, 120, 50);
 var slotsize : int;
 var spacing : int;
 var tempTex : Texture;
 var defaultTex : Texture;
 var pressed : boolean;
 var items : GameObject[];
 var dragobject : GameObject;
 
 var buttonClicked : boolean = false;
 var objAttached : boolean = false;
 var lastSlot : int;
 var slotMovedFlag : boolean = false;
 
 function OnGUI() {
 GUI.skin = style;
 if(openInv) {
 windowRect = GUI.Window(0, windowRect, DoMyWindow, "Inventory");
 }
 }
 
 function DoMyWindow (windowID : int) {
 for(var i = 0; i < 4; i++) {
 for(var j = 0; j < 4; j++) {
 if(items[16 + (4 * i) + j  - 21] == null)// error is here {
 tempTex = defaultTex;
 }
 else {
 tempTex = items[16 + (4 * i) + j - 21].GetComponent("itemStats").itemSlottex;
 }
 if(Input.GetMouseButtonDown(0)) {
 SetButtonClicked(false);
 }
 if(GUI.Button(Rect(slotsize * j + spacing * (j+1), slotsize * i + spacing * (i+1) + 15, slotsize, slotsize), tempTex)) {
 SetButtonClicked(true);
 if(items[16 + (4 * i) + j - 21] != null) {
 dragobject.SetCursor(items[16 + (4 * i) + j - 21].GetComponent("itemStats").itemSlottex);
 SetObjAttached(true);
 lastSlot = 16 + (4 * i) + j - 21;
 }
 MoveSlot(16 + (4 * i) + j - 21);
 }
 }
 }
 }
 
 function MoveSlot(indSlot : int) {
 if(items[indSlot] == null && !GetSlotMovedFlag()) {
 SetObjectInBag(indSlot, items[GetLastSlotUsed()]);
 ReleaseSlot(lastSlot);
 SetSlotMovedFlag(true);
 dragobject.getComponent("Drag").ReleaseCursorIcon();
 SetObjAttached(false);
 }
 else if(items[indSlot] != null && items[GetLastSlotUsed()] != null && !GetSlotMovedFlag()) {
 var tmpObj : GameObject = GetObjectsInBag(indSlot);
 SetObjectInBag(indSlot, items[GetLastSlotUsed()]);
 SetObjectInBag(lastSlot, tmpObj);
 SetSlotMovedFlag(true);
 dragobject.getComponent("Drag").ReleaseCursorIcon();
 SetObjAttached(false);
 }
 else {
 SetSlotMovedFlag(false);
 }
 SetLastSlotUsed(indSlot);
 }
 
 function ReleaseSlot(index : int) {
 SetObjectInBag(index, null);
 }
 
 function AddItem() {
 if(full == false) {
 newItem.parent = invParent;
 noItems++;
 items.Add(newItem);
 }
 }
 
 function RemoveItem() {
 var script : itemStats = itemSelected.gameObject.GetComponent("itemStats");
 script.useable = false;
 yield WaitForSeconds(throwTime);
 itemSelected.parent = null;
 noItems--;
 }
 
 function Update() {
 if(noItems >= maxSlots) {
 full = true;
 }
 else {
 full = false;
 }
 if(noItems <= minSlots) {
 noItems = minSlots;
 }
 if(Input.GetKey("i") && openInv == false && pressed == false) {
 openInv = true;
 wait();
 }
 else if(Input.GetKey("i") && openInv == true && pressed == false) {
 openInv = false;
 wait();
 }
 }
 
 function wait() {
 pressed = true;
 yield WaitForSeconds(0.3);
 pressed = false;
 }
 
 function GetObjectsInBag(t : int) {
 return items[t];
 }
 
 function SetObjectInBag(t : int, obj : GameObject) {
 items[t] = obj;
 }
 
 function SetLastSlotUsed(t : int) {
 lasSlotUsed = t;
 }
 function GetLastSlotUsed() {
 return lastSlot;
 }
 function SetSlotMovedFlag(val : boolean) {
 slotMovedFlag = val;
 }
 function GetSlotMovedFlag() {
 return slotMovedFlag;
 }
 function GetButtonClicked() {
 return buttonClicked;
 }
 function SetButtonClicked(val : boolean) {
 butonClicked = val;
 }
 function GetObjectAttached() {
 return objAttached;
 }
 function SetObjAttached(val : boolean) {
 objAttached = val;
 }