I am trying to do some basic interactions with Zotero via javascript - for example adding a record. I tried the example code from:
http://dev.zotero.org/interacting_with_zotero_from_within_firefox

And did the following:

var Zotero = Components.classes["@zotero.org/Zotero;1"]
				.getService(Components.interfaces.nsISupports)
				.wrappedJSObject;
var data = {
    title: "Much Ado About Nothing",
    creators: [
        ['William', 'Shakespeare', 'author']
    ]
};
var item = Zotero.Items.add('book', data);

But get the following error:
Error: Permission denied to get property XPCComponents.classes

Can someone post some basic sample js code that interacts with Zotero?

Thanks
Andrew