Sound as property in class?

I have a class where a property is a sound variable, but it doesn’t work.

Is this possible and I’m doing something wrong or will this never work?

Here is an example:

ActionScript Code:
[LEFT][FONT=Courier New][COLOR=#000000]class[/COLOR] exampleClass[COLOR=#000000]{[/COLOR][/FONT]
[FONT=Courier New] [COLOR=#0000ff]private[/COLOR] [COLOR=#000000]var[/COLOR] _sound:[COLOR=#0000ff]Sound[/COLOR][/FONT]
[FONT=Courier New] [COLOR=#000000]function[/COLOR] exampleClassCOLOR=#000000[/COLOR][COLOR=#000000]{[/COLOR][/FONT]
[FONT=Courier New] [COLOR=#0000ff]this[/COLOR]._sound = [COLOR=#000000]new[/COLOR] [COLOR=#0000ff]Sound[/COLOR]COLOR=#000000[/COLOR][/FONT]
[FONT=Courier New] [COLOR=#000000]}[/COLOR][/FONT]
[FONT=Courier New][COLOR=#000000]function[/COLOR] [COLOR=#0000ff]loadSong[/COLOR]COLOR=#000000[/COLOR][COLOR=#000000]{[/COLOR][/FONT]
[FONT=Courier New] [COLOR=#0000ff]this[/COLOR]._sound.[COLOR=#0000ff]loadSound[/COLOR]COLOR=#000000[/COLOR][/FONT]
[FONT=Courier New] [COLOR=#000000]}[/COLOR][/FONT]
[FONT=Courier New]}[/FONT][/LEFT]

Anyonegot any ideas?