level loader script wont work

/ Example level loader /

// JavaScript function OnGUI () { // Make a background box GUI.Box (Rect (10,10,100,90), "Loader Menu");

 // Make the first button. If it is pressed, Application.Loadlevel (1) will be executed
 if (GUI.Button (Rect (20,40,80,20), "Level 1")) {
     Application.LoadLevel (1);
 }

 // Make the second button.
 if (GUI.Button (Rect (20,70,80,20), "Level 2")) {
     Application.LoadLevel (2);
 }

}

//C# using UnityEngine; using System.Collections;

public class GUITest : MonoBehaviour {

 void OnGUI () {
     // Make a background box
     GUI.Box(new Rect(10,10,100,90), "Loader Menu");

     // Make the first button. If it is pressed, Application.Loadlevel (1) will be executed
     if(GUI.Button(new Rect(20,40,80,20), "Level 1")) {
         Application.LoadLevel(1);
     }

     // Make the second button.
     if(GUI.Button(new Rect(20,70,80,20), "Level 2")) {
         Application.LoadLevel(2);
     }
 }

}

any help would be nice, please and thank you