How to CenterPanel one of the Tab to open another tab


this is my code:


<Center>
    <ext:TabPanel ID="CenterPanel" runat="server" EnableTabScroll="true">
        <Tabs>
            <ext:Tab ID="CenterTab1" runat="server" Title="Center" Border="false">
                <AutoLoad Url="SysCenter.aspx" Mode="IFrame" ShowMask="true" MaskMsg="wait..." />
            </ext:Tab>
        </Tabs>
    </ext:TabPanel>
</Center>


<script type="text/javascript">
    var loadPage = function(tabPanel, node) {
        var tab = tabPanel.getItem(node.id);
        if (!tab) {
            tab = tabPanel.add({
                id: node.id,
                title: node.text,
                closable: true,
                autoLoad: {
                    showMask: true,
                    url: node.attributes.href,
                    mode: 'iframe',
                    maskMsg: 'wait...'
                }
            });
        }
        tabPanel.setActiveTab(tab);
    }
</script>

thanks!