<zk>
	<zscript>
	EventQueue que = EventQueues.lookup("iframe", "group", true);
	void publish() {
		String text = tbx.getValue();
		que.publish(new Event("onGroupTest", null, text));
	}
	</zscript>
	<vlayout>
		<iframe width="400px" height="600px" src="iframe.zul" />
		<div>
			Please type some words into the textbox and then you should see NPE exception.
			<textbox id="tbx" onChange="publish()"/>
		</div>
	</vlayout>
</zk>

<zk>
	<window title="Iframe" border="normal" width="300px">
		<zscript>
		EventQueue que = EventQueues.lookup("iframe", "group", true);
		que.subscribe(new EventListener() {
			public void onEvent(Event evt) {
				lbl.setValue((String)evt.getData());
			}
		});
		</zscript>
		<textbox id="lbl" value="This is Iframe" />
	</window>
</zk>