Inventory question

I have been watching this unity tutorial on Youtube where you learn how to make an inventory. Everything has been going well until I watched Episode 7. I just can’t understand what I did wrong. I can’t see any difference with his script and my script. Unity3D Tutorial #107 [ Advanced Inventory Part 7 ] - YouTube
I know which part of the script is wrong, but I posted the whole script anyway.

import System.Collections.Generic;

//holding all our items
var items : Item[];
//inventory
var MainInventory : List. <Item> = new List.<Item>();

//Equip menu ( 0=hat, 1=helmet, 2= shoulders, 3=gloves, 4=pants, 5=boots, 6=ring, 7= neckless)
var EquipMenu : Item[];

function Start () {
	
	MainInventory.Add(items[0]);
	MainInventory.Add(items[1]);
}


function OnGUI () {
	
	for (var x = 0; x < MainInventory.Count; x++) {
	
		if(GUI.Button(Rect(Screen.width/2, Screen.height/ 2 + ( 20 * x),100,20), GUIContent ( MainInventory[x].Name,
		"Stanima: " + MainInventory[x].Stamina + "

" +
"Power: " + MainInventory.Power + "
" +
"Attack Speed: " + MainInventory.attackSpeed + "
" +
"Rarity: " + MainInventory.rarity))) {

			if (MainInventory[x].itemType == MainInventory[x].itemType.helmet) {
	 				
				EquipMenu[0] = MainInventory[x];
				MainInventory.RemoveAt(x);
				}
				else if (MainInventory[x].itemType == MainInventory[x].itemType.shoulders) { 
					EquipMenu[1] = MainInventory[x];
					MainInventory.RemoveAt(x);		
				}												
		}
		GUI.Label(Rect(Screen.width/2 + 70, Screen.height/ 2 + ( 20 * x),300,300), GUI.tooltip);
	}
	for (var y = 0; y < EquipMenu.length; y++) {
		
		if (EquipMenu[y] != null);
			
			if(GUI.Button(Rect(Screen.width/2 - 150, Screen.height/ 2 + ( 20 * y),100,20), "" + EquipMenu[y].name)) {
				
				MainInventory.Add(EquipMenu[y]);
				EquipMenu[y] = null;
				}
			}
		}

Note: I know that I did the second script right because it otherwise wouldn’t work in the previous videos in the tutorial if I wrote it wrong.

Translate import System… to using System… in the first line