Cannot Call java from javascript

<?page contentType="text/html;charset=UTF-8"?>
<zk>
<script type="text/javascript">
		
			pm.bind("ComponentToParent", function(data) {
			  alert("FROM CHILD: " + JSON.stringify(data));
			  zAu.send(new zk.Event(zk.Widget.$(this), 'onMessage', JSON.stringify(data)));
			  alert("EVENT SEND!");
			});
			
			...
	
		</script>
		
	<window id="windowComponent" border="none" apply="ComponentController" style="background:transparent;">
		...
	</window>
</zk>

public class ComponentController extends GenericAutowireComposer {


	public void doAfterCompose(Component component) throws Exception {
         super.doAfterCompose(component);

		component.addEventListener("onMessage",
            new EventListener() {
                public void onEvent(Event event) throws Exception {
                	onMessage();
                }
            });
    }
	
	public void onMessage() throws InterruptedException {
		Messagebox.show("MESSAGE FROM CHILD RECEIVED IN PARENT'S JAVA");
	}
}