1) <action method="addJs"><script>js/yourfile.js</script></action>

2) <action method="addCss"><stylesheet>css/yourstyle.css</stylesheet></action>

3) OR

4) <action method="addItem"><type>skin_js</type><name>js/ yourfile.js</name></action>

5) <action method="addItem"><type>skin_css</type><name>css/yourstyle. css</name></action>