Application.LoadLevel obsolete but SceneManager.LoadScene Doesn't work

So this is probably a stupid question but i’m stumped. So i tried to run this using Application.LoadLevel to load this but unity tell me that using that method is obsolete and said to use scenemanager.loadscene instead however i get the error.
CS0103 The name ‘SceneManager’ does not exist in the current context

i really and stumped and dont know what to do…

using UnityEngine;
using System.Collections;

public class ClickToChange : MonoBehaviour {
    void OnMouseDown()

You’re missing:

using UnityEngine.SceneManagement;

at the top of your class.

I remember hearing about the multi-scene feature in a live training course, did not know that update happened. Good to know thanks!

Application.LoadLevel is giving me crashes under Unity 5.3.1f1 (64-bit) so I suggest we all move to using the using UnityEngine.SceneManagement a.s.a.p.

looks like the updated version of Application.LoadLevel (SceneManager.LoadScene) only works in c#

why switching?!
load level was good right?