@script RequireComponent(AudioSource) does not work

Hi,

I´m going through the Unity Game Dev Essentials right now and having a little problem with the

@script RequireComponent(AudioSource)

command.

It simply doesn´t work. In Chapter 8, there is this simple script:

 var levelToLoad : String;
 var normalTexture : Texture2D;
 var rollOverTexture : Texture2D;
 var beep : AudioClip;
 
 function OnMouseEnter(){
     guiTexture.texture = rollOverTexture;
 }
 
 function OnMouseExit(){
     guiTexture.texture = normalTexture;
 }
 
 function OnMouseUp(){
     audio.PlayOneShot(beep);
     yield new WaitForSeconds(0.35);
     Application.LoadLevel(levelToLoad);
 }
 
 @script RequireComponent(AudioSource)

which should add an Audio Source component to an object, after the script is added. Well, it doesn´t work for some reason and I can´t find out why. Anyone knows what could cause it not to appear in the inspector ? :(

Thanks for help in advance !