Status Label does not display inside pop-up Window

<?xml version="1.0" encoding="UTF-8"?>
<zk xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
    xmlns='http://www.zkoss.org/2005/zul'
    xmlns:h='http://www.w3.org/1999/xhtml'
    xsi:schemaLocation='http://www.zkoss.org/2005/zul WEB-INF/xsd/zul.xsd'
    anyAttribute= " ">


<window id='testWin' use='ControllerTestWin' 
        border='normal' title='A Test Page'>
  <label value='Select a category:'/><separator/>
  <!-- This is the movie category List box -->
  <listbox id='categoryLstBox' mold="select" rows="1"
     onSelect='testWin.categoryLstBox_onSelect()'>
     <listitem label='Cartoons' value='C' selected='true'/>
     <listitem label='ActionMovies' value='A' />
  </listbox>
  <!-- CLick this button to display the Category movie details -->
  <space spacing='1px'/>
  <button id='displayBtn' label='Display Detail' autodisable='self'
     onClick='testWin.displayBtn_onClick()'/>
  <!--  Deselect button that simulates some actions on the selected records -->
  <space spacing='1px'/>
  <button id='unselectBtn' label='UnSelect Records' autodisable='self'
     onClick='testWin.unselectBtn_onClick()'/>
  <!-- Edit button to edit the selected row -->
  <space spacing='1px'/>
  <button id='editBtn' label='Edit Record' autodisable='self'
     onClick='testWin.editBtn_onClick()'/>
  <!-- This listbox display the movies names per selected Category -->
  <separator/>
  <listbox id='detailLstBox' width='400px' checkmark='true' multiple='true'>
    <listhead sizable='true'>
      <listheader label='Name'/>
    </listhead>
  </listbox>

  <!-- ========= Pop-up window to edit selected record ============ -->
        <window id='subEditWin' visible='false' width='500px'
                border='normal' title='Edit Window' >
          
          <label value='Movie name:'/>
          <textbox id='movieNameTxtBox' width='80%' constraint='no empty'/>

          <separator/>
          <h:center>
            <label id='statusLbl'/>
            <button id='saveEditBtn' label='Save Record'
                    onClick='testWin.saveEditBtn_onClick()'/>
            <button id='closeSubWinBtn' label='Close Window'
                    onClick='testWin.closeSubWinBtn_onClick()'/>
          </h:center>
        </window>
  <!-- ========= End of pop-up Window ============ -->
</window>
</zk>

import java.sql.SQLException;
import javax.servlet.ServletContext;
import java.util.*;
import org.zkoss.zul.*;
import org.zkoss.zk.ui.*;
import org.zkoss.zk.ui.event.*;
import org.zkoss.zk.ui.event.EventListener;

/** Controller class for the verifyWindow page */

public class ControllerTestWin extends Window {
  private ZKCommonUtils zkCommonUtils = new ZKCommonUtils();
  private Map<String, String[]> nameHash = Collections.synchronizedMap(new HashMap());
  private int existingSelectIndex = 0;
  /**  Constructor */
  public ControllerTestWin() {
    this.nameHash.put("C", new String[] {"Tom And Jerry", "Tweety and Sylvester", "Looney Toons"});
    this.nameHash.put("A", new String[] {"Enter the Dragon", "Rumble in the Bronx", "Kickboxer"});
  }//end constructor
  /** ===================Getter and Setter=============================== */
  
  //===========================================================================
  private Listbox getCategoryLstBox() throws Exception {
    return (Listbox) getFellow("categoryLstBox");  
  }//end method
  private Button getDisplayBtn() throws Exception {
    return (Button) getFellow("displayBtn");  
  }//end method
  private Listbox getDetailLstBox() throws Exception {
    return (Listbox) getFellow("detailLstBox");  
  }//end method
  private Window getSubWin() throws Exception {
    return (Window) getFellow("subEditWin");
  }//end method
  private Textbox getSubWinTxtBox(Window subWin) throws Exception {
    return (Textbox) subWin.getFellow("movieNameTxtBox");
  }//end method
  private Button getSubWinSaveBtn(Window subWin) throws Exception {
    return (Button) subWin.getFellow("saveEditBtn");
  }//end method
  private Label getSubWinStatusLbl(Window subWin) throws Exception {
    return (Label) subWin.getFellow("statusLbl");
  }//end method
  // ======================Event Handlers======================================        
  public void categoryLstBox_onSelect() throws Exception {
    if (this.getDetailLstBox().getSelectedItems().isEmpty()) {
      this.existingSelectIndex = this.getCategoryLstBox().getSelectedItem().getIndex();
    }//if no record selected
    else {
      Messagebox.show("There are still selected rows in the main table. \n " +
                      "Click YES if you want to proceed without saving or \n " +
                      "Click NO to go back and finish your work.",
                      "Confirmation Prompt",
                      Messagebox.YES | Messagebox.NO,
                      Messagebox.QUESTION,
                      new EventListener() {
                        public void onEvent(Event evt) throws Exception{
                          switch (((Integer) evt.getData()).intValue()) {
                          case Messagebox.YES:
                            existingSelectIndex = getCategoryLstBox().getSelectedItem().getIndex();
                            getDetailLstBox().getChildren().clear();
                            break;
                          case Messagebox.NO:
                            //restore the previous selected item
                            getCategoryLstBox().setSelectedIndex(existingSelectIndex);
                            break;
                          }//end switch
                        }//end onEvent()
                      }//end EventListener instance
                      );
      
    }//end if there're selected records
  }//end method

  public void displayBtn_onClick() throws Exception {
    String categoryKey = (String) this.getCategoryLstBox().getSelectedItem().getValue();  
    String[] categoryValue = this.nameHash.get(categoryKey);
    this.getDetailLstBox().getChildren().clear();
    for (int i=0; i < categoryValue.length; i++){
      Listitem listItem = new Listitem(categoryValue<i >, categoryValue<i >);
      listItem.setParent(this.getDetailLstBox());
    }//end for
  }//end method

  public void editBtn_onClick() throws Exception {
    if (this.getDetailLstBox().getSelectedItem() != null) {
      this.getSubWinStatusLbl(this.getSubWin()).setValue("");
      this.getSubWinTxtBox(this.getSubWin()).setValue(
        (String) this.getDetailLstBox().getSelectedItem().getValue()
                                                    );
      this.getSubWin().doModal();
    }
  }//end method

  public void unselectBtn_onClick() throws Exception {
    this.getDetailLstBox().clearSelection();
  }//end method

  public void saveEditBtn_onClick() throws Exception {
    this.getSubWinStatusLbl(this.getSubWin()).setValue("Processing...");
    //Simulate some processing time after user edit the record and save
    Thread.sleep(5000);
    this.getSubWinStatusLbl(this.getSubWin()).setValue("Done!!");
  }//end method

  public void closeSubWinBtn_onClick() throws Exception {
    this.getSubWin().setVisible(false);
  }//end method

}//end class