Closing a document within Javascript.

I'm new here and new to javascripting in photoshop (though not new to javascript).

I've been trying to figure out how to do the equivalent of either the "File>Close" or the "File>Close All" menu item. Preferably programmatically specifying changes not be saved as the script will have saved what it wanted saved before closing.

I can't find a sample of this nor could I find other references to it in the forum. I'd appreciate any help that can be provided for this.

Thanks,

Steve Ellis.