Changing uGUI Image sprite during runtime

Hey,
I'm trying to change a UI Image sprite using script but nothing seems to work
this is my code

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.UI;
3. using System.Collections;
4.  
5. public class SLOT : MonoBehaviour {
6.     public Image Item; // I have attached the target UI Image using the inspector
7.  
8.     void Start () {
9.         Item.overrideSprite = (Sprite)Resources.Load("Sprites/100");
10.     }

I've also set the target image to "Sprite (2D and UI)"
I tried using .sprite instead of .overrideSprite but it didnt work as well..

 

what's the type of return from Resources.Load("Sprites/100")? I must be a texture, and it can not be converted to sprite

 

Code (CSharp):

1. image.sprite = (Sprite)Resources.Load("Sprites/spriteName", typeof(Sprite));

This will be work.You should tell it which type of Source will be Load.