Portalchildren visible false problem

<zk>
	<zscript><![CDATA[
		Panel panel1, panel2, panel3;
		void init() {
			panel1 = createPanel("panel1", "Panel 1");
			panel2 = createPanel("panel2", "Panel 2");
			panel3 = createPanel("panel3", "Panel 3");
			bussinessPortal.setPanel(panel1, 0, 0);
			bussinessPortal.setPanel(panel2, 0, 1);
			bussinessPortal.setPanel(panel3, 1, 0);
		}
		Panel createPanel( String id, String title ) {
			String content = "<panel height=\"300px\" border=\"normal\"><panelchildren></panelchildren></panel>";
			Panel panel = (Panel) Executions.createComponentsDirectly(content, null, null, null);
			panel.setId(id);
			panel.setTitle(title);
			return panel;
		}
	]]></zscript>
    <radiogroup id="columnSelect">
        <hlayout>
            <groupbox height="40px" width="200px" closable="false">
                <caption label="Columns" />
                <button id="singleColumnBtn" label="single column">
                	<attribute name="onClick"><![CDATA[
						ptc1.setWidth("100%");
						ptc2.setVisible(false);
						singleColumnBtn.setDisabled(true);
						twoColumnBtn.setDisabled(false);
                	]]></attribute>
                </button>
                <button id="twoColumnBtn" label="two columns" disabled="true">
                	<attribute name="onClick"><![CDATA[
						ptc1.setWidth("50%");
						ptc2.setWidth("50%");
						ptc2.setVisible(true);
						singleColumnBtn.setDisabled(false);
						twoColumnBtn.setDisabled(true);
                	]]></attribute>
                </button>
            </groupbox>
        </hlayout>
    </radiogroup>
    <portallayout id="bussinessPortal" maximizedMode="whole">
    	<attribute name="onCreate"><![CDATA[
			init();
		]]></attribute>
        <portalchildren id="ptc1" width="50%" style="padding:5px;" />
        <portalchildren id="ptc2" width="50%" style="padding:5px;" />
    </portallayout>
</zk>