How to detach / reattach MVVM windows?

<?page title="Main View" contentType="text/html;charset=UTF-8"?>
<zk>
<window id="winMainView" title="Main View" border="normal" height="100%" width="100%" 
		apply="org.zkoss.bind.BindComposer"	
		viewModel="@id('vm') @init('test.MainViewVM')" >

	<borderlayout>
		<north height="48px" border="none">
			<vlayout>
				<label value="This is the Main View" />
			</vlayout>
		</north>
		
		<center border="none">
			<div id="divWorkspace" vflex="true" />
		</center>
	</borderlayout>
</window>
</zk>

package test;
import org.zkoss.bind.annotation.AfterCompose;
import org.zkoss.bind.annotation.ContextParam;
import org.zkoss.bind.annotation.ContextType;
import org.zkoss.bind.annotation.GlobalCommand;
import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.Executions;
import org.zkoss.zk.ui.select.Selectors;
import org.zkoss.zk.ui.select.annotation.Wire;
import org.zkoss.zul.Div;
import org.zkoss.zul.Window;

public class MainViewVM {
	
	@Wire 
	private Div divWorkspace;
	
	/*
	 * The window representing the 'search' sub-view 
	 */
	private Window wSearchView;
	
	/*
	 * The window representing the 'detail' sub-view 
	 */
	private Window wDetailView;
	
	@AfterCompose
	public void init(@ContextParam(ContextType.VIEW) Component view)
	{
		Selectors.wireComponents(view, this, false);
		
		/*
		 * create the search-view
		 */
		wSearchView = (Window) Executions.createComponents("/test/search-view.zul", divWorkspace, null);
	}
	
	@GlobalCommand
	public void openDetailView() {
		wSearchView.detach();
		wDetailView = (Window) Executions.createComponents("/test/detail-view.zul", divWorkspace, null);
	}
	
	@GlobalCommand
	public void reattachSearchView() {
		wDetailView.detach();
		wSearchView.setParent( divWorkspace );
	}
}

<?page title="Search" contentType="text/html;charset=UTF-8"?>
<zk>
<window id="winSearch" title="Search" border="normal"
		apply="org.zkoss.bind.BindComposer"	
		viewModel="@id('vm') @init('test.SearchViewVM')" >
	
	<vlayout>
		<label value="This is the 'search' view embedded inside the main div" />
		<button label="Close 'search' view and open the 'detail' view" onClick="@command('close')" />
	</vlayout>
</window>
</zk>

package test;
import org.zkoss.bind.BindUtils;
import org.zkoss.bind.annotation.Command;

public class SearchViewVM {
	
	@Command
	public void close() {
		BindUtils.postGlobalCommand(null, null, "openDetailView", null);
	}

}

<?page title="Detail" contentType="text/html;charset=UTF-8"?>
<zk>
<window id="winDetail" title="Search" border="normal"
		apply="org.zkoss.bind.BindComposer"	
		viewModel="@id('vm') @init('test.DetailViewVM')" >
	
	<vlayout>
		<label value="This is the 'detail' view embedded inside the main div" />
		<button label="Close 'detail' view and try to re-attach the 'search view" onClick="@command('close')" />
	</vlayout>
</window>
</zk>

package test;
import org.zkoss.bind.BindUtils;
import org.zkoss.bind.annotation.Command;

public class DetailViewVM {
	
	@Command
	public void close() {
		BindUtils.postGlobalCommand(null, null, "reattachSearchView", null);
	}
	
}