JsonUtilty not found

I am trying to use JsonUtility.fromJson which according to the docs looks like it comes form UnityEngine which I am using. I am getting the error message: "the type or namespace name ‘JsonUtility’ can not be found… What am I doing wrong?

Thanks

The JsonUtility class wasn’t added until version 5.3.0. Check which version of Unity you’re using in the Editor by going to Help->About Unity…

The online documentation is for the current version of Unity, which may not be the same as the one you are using.

This link shows changes to the API by version number:

http://docs.unity3d.com/ScriptReference/40_history.html