<zk>
<zscript>
<![CDATA[  //@IMPORT
import org.zkoss.zk.ui.event.EventListener;
]]>
<![CDATA[  //@DECLARATION

  Window win = null;

  public class MyListener implements EventListener{
   	public void onEvent(Event evt) throws Exception{

       if (win ==null)
       {	   
         win = new Window();
         win.setTitle("Hello!");
         win.setClosable(true);

		 Label testLabel = new Label("My Label");
		 testLabel.setStubonly("true");
         win.appendChild(testLabel);
       }
       win.setParent(evt.getTarget().getFellow("mainWindow"));
       win.doModal();
    }
 }
]]>
</zscript>

<window id="mainWindow">
<button>Click me!
	<attribute name="onCreate">
		self.addEventListener("onClick", new MyListener(){});
	</attribute>
</button>
</window>
</zk>