How to replace contents of a panel

Hello, 

I have created a GUI application frame with a border layout.  I am
trying to replace the panel that was is in the "center" of the frame's
border layout depending on which button I press in a toolbar. 

I am able to initally render the GUI without any problems.  I am using
actionCommands for the buttons, and I'm not having any problem detecting
which button is pressed. 

I also don't have any problem finding the panel that I want it's
contents to be replaced with.  My problems start when I try to replace
the contents of the panel.  


This is the line of code that obtains the panel... 

savedPanel = (JPanel)getEngine().find("application_panel");


This is the code I'm using to insert GUI components into the
savedPanel....

savedPanel.removeAll();
try {
    getEngine().insert("guixml/dnssplitpane.xml", savedPanel);
    savedPanel.repaint();
}
catch(Exception ex) {
    ex.printStackTrace();
}


Replacing the contents within a panel seems to be a fairly common task. 
A more classic example would be a split pane with a tree on the left and
a panel on the right.  The contents of the panel on the right would
change depending on which node in the tree was selected.  One selected
node might result in a table being displayed in the right panel, while
selecting another node might result in a set of editable text fields,
etc... 

Any pointers, tips, or existing examples would be greatly appreciated. 


This is the main panel.....

<panel id="DNS_MAIN_PANEL"
       layout="BorderLayout"
       constraints="BorderLayout.CENTER">
  <panel id="pnl_North" 
         layout="borderlayout" 
         constraints="BorderLayout.NORTH">
      <toolbar id="tb" 
               floatable="true" 
               borderPainted="true" 
               orientation="HORIZONTAL"
               layout="BorderLayout">
        <panel constraints="BorderLayout.CENTER" background="white"/>
        <panel constraints="BorderLayout.EAST"
               background="white"
               layout="FlowLayout">
         <button id="manage_btn"
                 ToolTipText="Management" 
                 text="Management" 
                 focusPainted="false" 
                 enabled="true" 
                 icon="icons/new.gif" 
                 ActionCommand="manageAction"/>
        <separator/>
        <separator/>
        <button id="monitor_btn"
                ToolTipText="Monitoring" 
                text="Monitoring" 
                defaultCapable="false" 
                focusPainted="false" 
                enabled="true" 
                icon="icons/help.gif" 
                ActionCommand="monitorAction"/>
        <separator/>
        <separator/>
        <button id="admin_btn"
                ToolTipText="Administration" 
                text="Administration" 
                focusPainted="false" 
                selected="true"
                enabled="true" 
                icon="icons/exit.gif" 
                ActionCommand="adminAction"/>  
        <separator/>
        <separator/>
      </panel>   
    </toolbar>
  </panel>
  <panel id="application_panel"
         layout="Borderlayout" 
         constraints="BorderLayout.CENTER"
  </panel>
</panel>


This is the panel I'm trying to insert into "application_panel"

<?xml version="1.0" encoding="UTF-8"?>
 <panel constraints="BorderLayout.CENTER"
	    background="green"
		layout="BorderLayout" 
		id="PNL_SPLIT_PANE">
  <splitpane
		 constraints="BorderLayout.CENTER"
	     dividerlocation="400"
		 onetouchexpandable="true">
       <tabbedpane titles="ID Grid,Administrators">
		   <panel layout="BorderLayout">
            <scrollpane>		 		 
			  <tree showsroothandles="true"
				    selectionmode="1"
				    selectionrow="0"
					backgroundcolor="white"
					id="idgridtree"
					initclass="com.infoblox.gui.model.IdOneTreeModel">
			  </tree>
            </scrollpane>		 		 
		   </panel>
		   <panel layout="GridLayout(1,0)">
			  <scrollpane>
			  <table id="tbl" initclass="DNSTableModel">
			  </table>
			  </scrollpane> 
		   </panel>
	   </tabbedpane>	
	<scrollpane HorizontalScrollBarPolicy="32"
			    VerticalScrollBarPolicy="22">
	</scrollpane>		 		 
  </splitpane>
</panel>