<?xml version="1.0"?>
<layout version="0.1.0">
    <default>
    <reference name="head">
         <action method="addCss"><stylesheet>xzy/additionalstyles.css</stylesheet></action>
         <action method="addJs"><script>xzy/additionaljavascript.js</script></action>
    </reference>
    <reference name="after_body_start">
     <block type="core/template" before="-" as="additionaBlock" name="additionaBlock" template="xzy/additionalblock.phtml" />
    </reference>
</default>

</layout>