Someone

<?xml version="1.0"?>

<?xml-stylesheet href="chrome://global/skin/" type="text/css"?>

<window id="example-window" title="Example 4.3.1"
        xmlns:html="http://www.w3.org/1999/xhtml"
        xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
<script type="text/javascript">
	function closeTab()
		{
			alert("Wait... Closing the tab.. ");
		}
</script>
<tabbox>
  <tabs closebutton="true" onClick = "closeTab1();">
    <tab label="Mail" />
    <tab label="News"/>
  </tabs>
  <tabpanels>
    <tabpanel id="mailtab">
      <checkbox label="Automatically check for mail"/>
    </tabpanel>
    <tabpanel id="newstab">
      <button label="Clear News Buffer"/>
    </tabpanel>
  </tabpanels>
</tabbox>


</window>